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HP 40gs graphing calculator
user's guide
Edition1
Part Number F2225AA-90001
hp40g+.book Page i Friday, December 9, 2005 1:03 AM
Notice
REGISTER YOUR PRODUCT AT: www.register.hp.com
THIS MANUAL AND ANY EXAMPLES CONTAINED HEREIN ARE
PROVIDED "AS IS" AND ARE SUBJECT TO CHANGE WITHOUT
NOTICE. HEWLETT-PACKARD COMPANY MAKES NO WAR-
RANTY OF ANY KIND WITH REGARD TO THIS MANUAL,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY, NON-INFRINGEMENT AND FITNESS
FOR A PARTICULAR PURPOSE.
HEWLETT-PACKARD CO. SHALL NOT BE LIABLE FOR ANY
ERRORS OR FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES
IN CONNECTION WITH THE FURNISHING, PERFORMANCE, OR
USE OF THIS MANUAL OR THE EXAMPLES CONTAINED HEREIN.
© Copyright 1994-1995, 1999-2000, 2003, 2006 Hewlett-Packard Devel-
opment Company, L.P.
Reproduction, adaptation, or translation of this manual is prohibited without
prior written permission of Hewlett-Packard Company, except as allowed
under the copyright laws.
Hewlett-Packard Company
4995 Murphy Canyon Rd,
Suite 301
San Diego, CA 92123
Printing History
Edition 1 April 2005
title.fm Page ii Friday, February 17, 2006 9:48 AM
iii
Contents
Preface
Manual conventions .............................................................. P-1
Notice ................................................................................. P-2
1 Getting started
On/off, cancel operations......................................................1-1
The display ..........................................................................1-2
The keyboard .......................................................................1-3
Menus .................................................................................1-8
Input forms ...........................................................................1-9
Mode settings.....................................................................1-10
Setting a mode...............................................................1-11
Aplets (E-lessons).................................................................1-12
Aplet library ..................................................................1-16
Aplet views....................................................................1-16
Aplet view configuration..................................................1-18
Mathematical calculations....................................................1-19
Using fractions....................................................................1-25
Complex numbers ...............................................................1-29
Catalogs and editors ...........................................................1-30
2 Aplets and their views
Aplet views ..........................................................................2-1
About the Symbolic view ...................................................2-1
Defining an expression (Symbolic view) ..............................2-1
Evaluating expressions ......................................................2-3
About the Plot view...........................................................2-5
Setting up the plot (Plot view setup).....................................2-5
Exploring the graph..........................................................2-7
Other views for scaling and splitting the graph ..................2-13
About the numeric view...................................................2-16
Setting up the table (Numeric view setup) ..........................2-16
Exploring the table of numbers.........................................2-17
Building your own table of numbers..................................2-19
“Build Your Own” menu keys...........................................2-20
Example: plotting a circle ................................................2-20
3 Function aplet
About the Function aplet ........................................................3-1
Getting started with the Function aplet.................................3-1
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iv
Function aplet interactive analysis........................................... 3-9
Plotting a piecewise-defined function ................................ 3-12
4 Parametric aplet
About the Parametric aplet .................................................... 4-1
Getting started with the Parametric aplet............................. 4-1
5 Polar aplet
Getting started with the Polar aplet ......................................... 5-1
6 Sequence aplet
About the Sequence aplet...................................................... 6-1
Getting started with the Sequence aplet .............................. 6-1
7 Solve aplet
About the Solve aplet............................................................ 7-1
Getting started with the Solve aplet .................................... 7-2
Use an initial guess............................................................... 7-5
Interpreting results ................................................................ 7-6
Plotting to find guesses.......................................................... 7-7
Using variables in equations ................................................ 7-10
8 Linear Solver aplet
About the Linear Solver aplet ................................................. 8-1
Getting started with the Linear Solver aplet.......................... 8-1
9 Triangle Solve aplet
About the Triangle Solver aplet .............................................. 9-1
Getting started with the Triangle Solver aplet....................... 9-1
10 Statistics aplet
About the Statistics aplet...................................................... 10-1
Getting started with the Statistics aplet.............................. 10-1
Entering and editing statistical data ...................................... 10-6
Defining a regression model.......................................... 10-12
Computed statistics ........................................................... 10-14
Plotting............................................................................ 10-15
Plot types .................................................................... 10-16
Fitting a curve to 2VAR data ......................................... 10-17
Setting up the plot (Plot setup view) ................................ 10-18
Trouble-shooting a plot ................................................. 10-19
Exploring the graph ..................................................... 10-19
Calculating predicted values ......................................... 10-20
11 Inference aplet
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v
About the Inference aplet .....................................................11-1
Getting started with the Inference aplet .............................11-1
Importing sample statistics from the Statistics aplet ..............11-4
Hypothesis tests ..................................................................11-8
One-Sample Z-Test..........................................................11-8
Two-Sample Z-Test ..........................................................11-9
One-Proportion Z-Test....................................................11-10
Two-Proportion Z-Test ....................................................11-11
One-Sample T-Test ........................................................11-12
Two-Sample T-Test ........................................................11-14
Confidence intervals..........................................................11-15
One-Sample Z-Interval...................................................11-15
Two-Sample Z-Interval ...................................................11-16
One-Proportion Z-Interval...............................................11-17
Two-Proportion Z-Interval ...............................................11-17
One-Sample T-Interval ...................................................11-18
Two-Sample T-Interval....................................................11-19
12 Using the Finance Solver
Background........................................................................12-1
Performing TVM calculations ................................................12-4
Calculating Amortizations................................................12-7
13 Using mathematical functions
Math functions....................................................................13-1
The MATH menu ............................................................13-1
Math functions by category ..................................................13-2
Keyboard functions.........................................................13-3
Calculus functions...........................................................13-6
Complex number functions...............................................13-7
Constants ......................................................................13-8
Conversions...................................................................13-8
Hyperbolic trigonometry..................................................13-9
List functions ................................................................13-10
Loop functions..............................................................13-10
Matrix functions ...........................................................13-11
Polynomial functions .....................................................13-11
Probability functions......................................................13-12
Real-number functions ...................................................13-14
Two-variable statistics....................................................13-17
Symbolic functions........................................................13-17
Test functions ...............................................................13-19
Trigonometry functions ..................................................13-20
hp40g+.book Page v Friday, December 9, 2005 1:03 AM
vi
Symbolic calculations........................................................ 13-20
Finding derivatives....................................................... 13-21
Program constants and physical constants ........................... 13-24
Program constants........................................................ 13-25
Physical constants ........................................................ 13-25
14 Computer Algebra System (CAS)
What is a CAS? ................................................................. 14-1
Performing symbolic calculations .......................................... 14-1
An example .................................................................. 14-2
CAS variables.................................................................... 14-4
The current variable ....................................................... 14-4
CAS modes ....................................................................... 14-5
Using CAS functions in HOME............................................. 14-7
Online Help....................................................................... 14-8
CAS functions in the Equation Writer .................................... 14-9
ALGB menu................................................................. 14-10
DIFF menu................................................................... 14-16
REWRI menu ............................................................... 14-28
SOLV menu................................................................. 14-33
TRIG menu .................................................................. 14-38
CAS Functions on the MATH menu ..................................... 14-45
Algebra menu ............................................................. 14-45
Complex menu ............................................................ 14-45
Constant menu ............................................................ 14-46
Diff & Int menu ............................................................ 14-46
Hyperb menu .............................................................. 14-46
Integer menu ............................................................... 14-46
Modular menu............................................................. 14-51
Polynomial menu ......................................................... 14-55
Real menu................................................................... 14-60
Rewrite menu .............................................................. 14-60
Solve menu ................................................................. 14-60
Tests menu .................................................................. 14-61
Trig menu ................................................................... 14-61
CAS Functions on the CMDS menu ..................................... 14-62
15 Equation Writer
Using CAS in the Equation Writer ....................................... 15-1
The Equation Writer menu bar......................................... 15-1
Configuration menus ...................................................... 15-3
Entering expressions and subexpressions............................... 15-5
How to modify an expression ....................................... 15-11
hp40g+.book Page vi Friday, December 9, 2005 1:03 AM
vii
Accessing CAS functions....................................................15-12
Equation Writer variables .................................................15-16
Predefined CAS variables .............................................15-16
The keyboard in the Equation Writer ..............................15-17
16 Step-by-Step Examples
Introduction .......................................................................16-1
17 Variables and memory management
Introduction ........................................................................17-1
Storing and recalling variables .............................................17-2
The VARS menu ..................................................................17-4
Memory Manager...............................................................17-9
18 Matrices
Introduction ........................................................................18-1
Creating and storing matrices...............................................18-2
Working with matrices.........................................................18-4
Matrix arithmetic.................................................................18-6
Solving systems of linear equations...................................18-8
Matrix functions and commands..........................................18-10
Argument conventions...................................................18-10
Matrix functions ...........................................................18-10
Examples .........................................................................18-13
19 Lists
Displaying and editing lists...................................................19-4
Deleting lists ..................................................................19-6
Transmitting lists .............................................................19-6
List functions .......................................................................19-6
Finding statistical values for list elements ................................19-9
20 Notes and sketches
Introduction ........................................................................20-1
Aplet note view...................................................................20-1
Aplet sketch view ................................................................20-3
The notepad.......................................................................20-6
21 Programming
Introduction ........................................................................21-1
Program catalog ............................................................21-2
Creating and editing programs.............................................21-4
Using programs ..................................................................21-7
Customizing an aplet...........................................................21-9
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viii
Aplet naming convention .............................................. 21-10
Example ..................................................................... 21-10
Programming commands ................................................... 21-13
Aplet commands.......................................................... 21-14
Branch commands ....................................................... 21-17
Drawing commands ..................................................... 21-19
Graphic commands...................................................... 21-21
Loop commands .......................................................... 21-23
Matrix commands ........................................................ 21-24
Print commands ........................................................... 21-25
Prompt commands........................................................ 21-26
Stat-One and Stat-Two commands.................................. 21-29
Stat-Two commands ..................................................... 21-30
Storing and retrieving variables in programs ................... 21-31
Plot-view variables ....................................................... 21-31
Symbolic-view variables................................................ 21-38
Numeric-view variables ................................................ 21-40
Note variables............................................................. 21-43
Sketch variables .......................................................... 21-43
22 Extending aplets
Creating new aplets based on existing aplets......................... 22-1
Using a customized aplet................................................ 22-3
Resetting an aplet ............................................................... 22-3
Annotating an aplet with notes............................................. 22-4
Annotating an aplet with sketches......................................... 22-4
Downloading e-lessons from the web .................................... 22-4
Sending and receiving aplets............................................... 22-4
Sorting items in the aplet library menu list.............................. 22-6
Reference information
Glossary.............................................................................. R-1
Resetting the HP 40gs ........................................................... R-3
To erase all memory and reset defaults............................... R-3
If the calculator does not turn on........................................ R-4
Operating details ................................................................. R-4
Batteries ......................................................................... R-4
Variables............................................................................. R-6
Home variables ............................................................... R-6
Function aplet variables.................................................... R-7
Parametric aplet variables................................................. R-8
Polar aplet variables ........................................................ R-9
Sequence aplet variables................................................ R-10
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ix
Solve aplet variables.......................................................R-11
Statistics aplet variables ..................................................R-12
MATH menu categories .......................................................R-13
Math functions ...............................................................R-13
Program constants ..........................................................R-15
Physical Constants ..........................................................R-16
CAS functions ................................................................R-17
Program commands........................................................R-19
Status messages..................................................................R-20
Limited Warranty
Service.......................................................................... W-3
Regulatory Notices ......................................................... W-5
Index
hp40g+.book Page ix Friday, December 9, 2005 1:03 AM
hp40g+.book Page x Friday, December 9, 2005 1:03 AM
P-1
Preface
The HP 40gs is a feature-rich graphing calculator. It is
also a powerful mathematics learning tool, with a built-in
computer algebra system (CAS). The HP 40gs is designed
so that you can use it to explore mathematical functions
and their properties.
You can get more information on the HP 40gs from
Hewlett-Packard’s Calculators web site. You can
download customized aplets from the web site and load
them onto your calculator. Customized aplets are special
applications developed to perform certain functions, and
to demonstrate mathematical concepts.
Hewlett Packard’s Calculators web site can be found at:
http://www.hp.com/calculators
Manual conventions
The following conventions are used in this manual to
represent the keys that you press and the menu options
that you choose to perform the described operations.
Key presses are represented as follows:
, , , etc.
Shift keys, that is the key functions that you access by
pressing the key first, are represented as
follows:
CLEAR, MODES, ACOS, etc.
Numbers and letters are represented normally, as
follows:
5, 7, A, B, etc.
Menu options, that is, the functions that you select
using the menu keys at the top of the keypad are
represented as follows:
, , .
Input form fields and choose list items are represented
as follows:
Function, Polar, Parametric
Your entries as they appear on the command line or
within input forms are represented as follows:
2*X
2
-3X+5
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
P-2
Notice
This manual and any examples contained herein are
provided as-is and are subject to change without notice.
Except to the extent prohibited by law, Hewlett-Packard
Company makes no express or implied warranty of any
kind with regard to this manual and specifically disclaims
the implied warranties and conditions of merchantability
and fitness for a particular purpose and Hewlett-Packard
Company shall not be liable for any errors or for
incidental or consequential damage in connection with
the furnishing, performance or use of this manual and the
examples herein.
©
Copyright 1994-1995, 1999-2000, 2003, 2006
Hewlett-Packard Development Company, L.P.
The programs that control your HP 40gs are copyrighted
and all rights are reserved. Reproduction, adaptation, or
translation of those programs without prior written
permission from Hewlett-Packard Company is also
prohibited.
Preface.fm Page 2 Friday, February 17, 2006 9:47 AM
Getting started 1-1
1
Getting started
On/off, cancel operations
To turn on Press to turn on the calculator.
To cancel When the calculator is on, the key cancels the
current operation.
To turn off Press OFF to turn the calculator off.
To save power, the calculator turns itself off after several
minutes of inactivity. All stored and displayed information
is saved.
If you see the (()) annunciator or the Low Bat message,
then the calculator needs fresh batteries.
HOME HOME is the calculator’s home view and is common to all
aplets. If you want to perform calculations, or you want to
quit the current activity (such as an aplet, a program, or
an editor), press . All mathematical functions are
available in the HOME. The name of the current aplet is
displayed in the title of the home view.
Protective cover The calculator is provided with a slide cover to protect the
display and keyboard. Remove the cover by grasping
both sides of it and pulling down.
You can reverse the slide cover and slide it onto the back
of the calculator. this will help prevent you losing the
cover while you are using the calculator.
To prolong the life of the calculator, always place the
cover over the display and keyboard when you are not
using the calculator.
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
1-2 Getting started
The display
To adjust the
contrast
Simultaneously press and (or ) to increase (or
decrease) the contrast.
To clear the display Press CANCEL to clear the edit line.
Press
CLEAR to clear the edit line and the
display history.
Parts of the
display
Menu key or soft key labels. The labels for the menu
keys’ current meanings. is the label for the first
menu key in this picture. “Press ” means to press the
first menu key, that is, the leftmost top-row key on the
calculator keyboard.
Edit line. The line of current entry.
History. The HOME display ( ) shows up to four
lines of history: the most recent input and output. Older
lines scroll off the top of the display but are retained in
memory.
Title. The name of the current aplet is displayed at the top
of the HOME view. RAD, GRD, DEG specify whether
Radians, Grads or Degrees angle mode is set for HOME.
The
T and S symbols indicate whether there is more
history in the HOME display. Press the and to
scroll in the HOME display.
Title
Edit line
History
Menu key
labels
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Getting started 1-3
Annunciators. Annunciators are symbols that appear
above the title bar and give you important status
information.
The keyboard
Annunciator Description
Shift in effect for next keystroke.
To cancel, press again.
α Alpha in effect for next keystroke.
To cancel, press again.
(()) Low battery power.
Busy.
Data is being transferred.
Menu Key
Labels
Menu Keys
Cursor
Aplet Control
Alpha Key
Shift Key
Enter
Keys
Key
Keys
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
1-4 Getting started
Menu keys
On the calculator keyboard, the top row of keys are
called menu keys. Their meanings depend on the
context—that’s why they are blank. The menu keys
are sometimes called “soft keys.
The bottom line of the display shows the labels for the
menu keys’ current meanings.
Aplet control keys
The aplet control keys are:
Key Meaning
Displays the Symbolic view for the
current aplet. See “Symbolic view”
on page 1-16.
Displays the Plot view for the current
aplet. See “Plot view” on page 1-16.
Displays the Numeric view for the
current aplet. See “Numeric view” on
page 1-17.
Displays the HOME view. See
“HOME” on page 1-1.
Displays the Aplet Library menu. See
“Aplet library” on page 1-16.
Displays the VIEWS menu. See
“Aplet views” on page 1-16.
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Getting started 1-5
Entry/Edit keys
The entry and edit keys are:
Key Meaning
(
CANCEL)
Cancels the current operation if the
calculator is on by pressing .
Pressing , then
OFF turns the
calculator off.
Accesses the function printed in blue
above a key.
Returns to the HOME view, for
performing calculations.
Accesses the alphabetical
characters printed in orange below
a key. Hold down to enter a string
of characters.
Enters an input or executes an
operation. In calculations,
acts like “=”. When or
is present as a menu key,
acts the same as pressing or
.
Enters a negative number. To enter
–25, press 25. Note: this is not
the same operation that the subtract
button performs ().
Enters the independent variable by
inserting X, T, θ, or N into the edit
line, depending on the current
active aplet.
Deletes the character under the
cursor. Acts as a backspace key if
the cursor is at the end of the line.
CLEAR
Clears all data on the screen. On a
settings screen, for example Plot
Setup, CLEAR returns all
settings to their default values.
, , ,
Moves the cursor around the
display. Press first to move to
the beginning, end, top or bottom.
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
1-6 Getting started
Shifted keystrokes
There are two shift keys that you use to access the
operations and characters printed above the keys:
and .
CHARS Displays a menu of all available
characters. To type one, use the
arrow keys to highlight it, and press
. To select multiple characters,
select each and press , then
press .
Key Meaning (Continued)
Key Description
Press the key to access the
operations printed in blue above the
keys. For instance, to access the
Modes screen, press , then
press . (MODES is labeled in
blue above the key). You do
not need to hold down when
you press HOME. This action is
depicted in this manual as “press
MODES.”
To cancel a shift, press again.
The alphabetic keys are also shifted
keystrokes. For instance, to type Z,
press Z. (The letters are
printed in orange to the lower right of
each key.)
To cancel Alpha, press
again.
For a lower case letter, press
.
For a string of letters, hold down
while typing.
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
Getting started 1-7
HELPWITH The HP 40gs built-in help is available in HOME only. It
provides syntax help for built-in math functions.
Access the HELPWITH command by pressing
SYNTAX and then the math key for which you require
syntax help.
Example Press SYNTAX
Note: Remove the left parenthesis from built-in
functions such as sine, cosine, and tangent before
invoking the HELPWITH command.
Note: In the CAS system, pressing the SYNTAX
will show the CAS help menu.
Math keys HOME ( ) is the place to do non-symbolic
calculations. (For symbolic calculations, use the computer
algebra system, referred throughout this manual as CAS).
Keyboard keys. The most common operations are
available from the keyboard, such as the arithmetic (like
) and trigonometric (like ) functions. Press
to complete the operation: 256
displays 16.
.
MATH menu. Press
to open the MATH
menu. The MATH menu is a
comprehensive list of math
functions that do not appear
on the keyboard. It also
includes categories for all other functions and constants.
The functions are grouped by category, ranging in
alphabetical order from Calculus to Trigonometry.
The arrow keys scroll through the list ( , )
and move from the category list in the left column
to the item list in the right column ( , ).
Press to insert the selected command onto the
edit line.
Press to dismiss the MATH menu without
selecting a command.
chapter-1.fm Page 7 Friday, December 16, 2005 2:20 PM
1-8 Getting started
Pressing displays the list of Program
Constants. You can use these in programs that
you develop.
Pressing displays a menu of physical
constants from the fields of chemistry, physics,
and quantum mechanics. You can use these
constants in calculations. (pSee “Physical
constants” on page 13-25 for more information.)
Pressing takes you to the beginning of the
MATH menu.
See “Math functions by category” on page 13-2 for
details of the math functions.
HINT
When using the MATH menu, or any menu on the
HP 40gs, pressing an alpha key takes you straight to the
first menu option beginning with that alpha character.
With this method, you do not need to press first.
Just press the key that corresponds to the command’s
beginning alpha character.
Note that when the MATH menu is open, you can also
access CAS commands. You do this by pressing .
This enables you to use CAS commands on the HOME
screen, without opening CAS. See Chapter 14 for details
of CAS commands.
Program
commands
Pressing CMDS displays the list of Program
Commands. See “Programming commands” on
page 21-13.
Inactive keys If you press a key that does not operate in the current
context, a warning symbol like this appears. There is
no beep.
Menus
A menu offers you a choice
of items. Menus are
displayed in one or two
columns.
The arrow in the
display means more
items below.
The arrow in the
display means more items above.
!
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
Getting started 1-9
To search a menu Press or to scroll through the list. If you press
or , you’ll go all the way to
the end or the beginning of the list. Highlight the item
you want to select, then press (or ).
If there are two columns, the left column shows
general categories and the right column shows
specific contents within a category. Highlight a
general category in the left column, then highlight an
item in the right column. The list in the right column
changes when a different category is highlighted.
Press or when you have highlighted your
selection.
To speed-search a list, type the first letter of the word.
For example, to find the Matrix category in ,
press , the Alpha “M” key.
To go up a page, you can press . To go
down a page, press .
To cancel a menu Press (for CANCEL) or . This cancels the
current operation.
Input forms
An input form shows several fields of information for you
to examine and specify. After highlighting the field to
edit, you can enter or edit a number (or expression). You
can also select options from a list ( ). Some input
forms include items to check ( ). See below for
examples input forms.
Reset input form
values
To reset a field to its default values in an input form, move
the cursor to that field and press . To reset all default
field values in the input form, press CLEAR.
hp40g+.book Page 9 Friday, December 9, 2005 1:03 AM
1-10 Getting started
Mode settings
You use the Modes input form to set the modes for HOME.
HINT
Although the numeric setting in Modes affects only
HOME, the angle setting controls HOME and the current
aplet. The angle setting selected in Modes is the angle
setting used in both HOME and current aplet. To further
configure an aplet, you use the
SETUP keys (
and ).
Press
MODES to access the HOME MODES input
form.
Setting Options
Angle
Measure
Angle values are:
Degrees. 360 degrees in a circle.
Radians. 2π radians in a circle.
Grads. 400 grads in a circle.
The angle mode you set is the angle
setting used in both HOME and the
current aplet. This is done to ensure
that trigonometric calculations done in
the current aplet and HOME give the
same result.
Number
Format
The number format mode you set is the
number format used in both HOME
and the current aplet.
Standard. Full-precision display.
Fixed. Displays results rounded to a
number of decimal places. Example:
123.456789 becomes 123.46 in
Fixed 2 format.
Scientific. Displays results with an
exponent, one digit to the left of the
decimal point, and the specified
number of decimal places. Example:
123.456789 becomes 1.23E2 in
Scientific 2 format.
hp40g+.book Page 10 Friday, December 9, 2005 1:03 AM
Getting started 1-11
Setting a mode
This example demonstrates how to change the angle
measure from the default mode, radians, to degrees for
the current aplet. The procedure is the same for changing
number format and decimal mark modes.
1. Press
MODES to open the HOME MODES input
form.
Engineering. Displays result with an
exponent that is a multiple of 3, and
the specified number of significant
digits beyond the first one. Example:
123.456E7 becomes 1.23E9 in
Engineering 2 format.
Fraction. Displays results as fractions
based on the specified number of
decimal places. Examples:
123.456789 becomes 123 in
Fraction 2 format, and .333 becomes
1/3 and 0.142857 becomes 1/7.
See “Using fractions” on page 1-25.
Mixed Fraction. Displays results as
mixed fractions based on the specified
number of decimal places. A mixed
fraction has an integer part and a
fractional part. Examples:
123.456789 becomes 123+16/35
in Fraction 2 format, and 7÷ 3 returns
2+1/3. See “Using fractions” on
page 1-25.
Decimal
Mark
Dot or Comma. Displays a number
as 12456.98 (Dot mode) or as
12456,98 (Comma mode). Dot mode
uses commas to separate elements in
lists and matrices, and to separate
function arguments. Comma mode
uses periods (dot) as separators in
these contexts.
Setting Options (Continued)
hp40g+.book Page 11 Friday, December 9, 2005 1:03 AM
1-12 Getting started
The cursor (highlight) is
in the first field, Angle
Measure.
2. Press to display a
list of choices.
3. Press to select
Degrees,
and press
. The angle measure
changes to degrees.
4. Press to return to
HOME.
HINT
Whenever an input form has a list of choices for a field,
you can press to cycle through them instead of using
.
Aplets (E-lessons)
Aplets are the application environments where you
explore different classes of mathematical operations. You
select the aplet that you want to work with.
Aplets come from a variety of sources:
Built-in the HP 40gs (initial purchase).
Aplets created by saving existing aplets, which have
been modified, with specific configurations. See
“Creating new aplets based on existing aplets” on
page 22-1.
Downloaded from HP’s Calculators web site.
Copied from another calculator.
Aplets are stored in the
Aplet library. See “Aplet
library” on page 1-16 for
further information.
You can modify
configuration settings for
the graphical, tabular, and
chapter-1.fm Page 12 Friday, December 9, 2005 1:26 AM
Getting started 1-13
symbolic views of the aplets in the following table. See
“Aplet view configuration” on page 1-18 for further
information.
In addition to these aplets, which can be used in a variety
of applications, the HP 40gs is supplied with two
teaching aplets: Quad Explorer and Trig Explorer. You
cannot modify configuration settings for these aplets.
A great many more teaching aplets can be found at HP’s
web site and other web sites created by educators,
together with accompanying documentation, often with
student work sheets. These can be downloaded free of
Aplet
name
Use this aplet to explore:
Function Real-valued, rectangular functions y in
terms of x. Example: .
Inference Confidence intervals and Hypothesis
tests based on the Normal and
Students-t distributions.
Parametric Parametric relations x and y in terms of
t. Example: x = cos(t) and y = sin(t).
Polar Polar functions r in terms of an angle θ.
Example: .
Sequence Sequence functions U in terms of n, or
in terms of previous terms in the same or
another sequence, such as and
. Example: , and
.
Solve Equations in one or more real-valued
variables. Example: .
Finance Time Value of Money (TVM)
calculations.
Linear
Solver
Solutions to sets of two or three linear
equations.
Triangle
Solver
Unknown values for the lengths and
angles of triangles.
Statistics One-variable (x) or two-variable (x and
y) statistical data.
y 2x
2
3x 5++=
r 24θ()cos=
U
n 1
U
n 2
U
1
0= U
2
1=
U
n
U
n 2
U
n
1
+=
x 1+ x
2
x–2=
hp40g+.book Page 13 Friday, December 9, 2005 1:03 AM
1-14 Getting started
charge and transferred to the HP 40gs using the provided
Connectivity Kit.
Quad Explorer
aplet
The Quad Explorer aplet is used to investigate the
behaviour of as the values of a, h and
v change, both by manipulating the equation and seeing
the change in the graph, and by manipulating the graph
and seeing the change in the equation.
HINT
More detailed documentation, and an accompanying
student work sheet can be found at HP’s web site.
Press , select Quad
Explorer, and then press
. The Quad Explorer
aplet opens in
mode, in which the arrow
keys, the and keys,
and the key are used to change the shape of the
graph. This changing shape is reflected in the equation
displayed at the top right corner of the screen, while the
original graph is retained for comparison. In this mode
the graph controls the equation.
It is also possible to have the
equation control the graph.
Pressing displays a
sub-expression of your
equation.
Pressing the and key moves between sub-
expressions, while pressing the and key changes
their values.
Pressing allows the user to select whether all three
sub-expressions will be explored at once or only one at a
time.
A button is provided to
evaluate the student’s
knowledge. Pressing
displays a target quadratic
graph. The student must
manipulate the equation’s parameters to make the
equation match the target graph. When a student feels
that they have correctly chosen the parameters a
button evaluates the answer and provide feedback. An
button is provided for those who give up!
yaxh+()
2
v+=
hp40g+.book Page 14 Friday, December 9, 2005 1:03 AM
Getting started 1-15
Trig Explorer aplet The Trig Explorer aplet is used to investigate the
behaviour of the graph of as the
values of a, b, c and d change, both by manipulating the
equation and seeing the change in the graph, or by
manipulating the graph and seeing the change in the
equation.
Press , select Trig
Explorer, and then press
to display the screen
shown right.
In this mode, the graph
controls the equation.
Pressing the and
keys transforms the
graph, with these
transformations reflected in the equation.
The button labelled is
a toggle between
and . When
is chosen, the ‘point of
control’ is at the origin (0,0)
and the and
keys control vertical and
horizontal transformations. When is chosen the
‘point of control’ is on the first extremum of the graph (i.e.
for the sine graph at .
The arrow keys change the
amplitude and frequency of
the graph. This is most easily
seen by experimenting.
Pressing displays the
equation at the top of the
screen. The equation is
controlled by the graph.
Pressing the and
keys moves from parameter
to parameter. Pressing the or key changes the
parameter’s values.
The default angle setting for this aplet is radians. The
angle setting can be changed to degrees by pressing
.
ya bxc+()d+sin=
Origin
π 21,()
Extremum
hp40g+.book Page 15 Friday, December 9, 2005 1:03 AM
1-16 Getting started
Aplet library
Aplets are stored in the Aplet library.
To open an aplet Press to display the Aplet library menu. Select the
aplet and press or .
From within an aplet, you can return to HOME any time
by pressing .
Aplet views
When you have configured an aplet to define the relation
or data that you want to explore, you can display it in
different views. Here are illustrations of the three major
aplet views (Symbolic, Plot, and Numeric), the six
supporting aplet views (from the VIEWS menu), and the
two user-defined views (Note and Sketch).
Note: some aplets—such as the Linear Solver aplet and
the Triangle Solver aplet—only have a single view, the
Numeric view.
Symbolic view Press to display the aplet’s Symbolic view.
You use this view to define
the function(s) or equation(s)
that you want to explore.
See “About the Symbolic
view” on page 2-1 for
further information.
Plot view Press to display the aplet’s Plot view.
In this view, the functions that
you have defined are
displayed graphically.
See “About the Plot view” on
page 2-5 for further
information.
hp40g+.book Page 16 Friday, December 9, 2005 1:03 AM
Getting started 1-17
Numeric view Press to display the aplet’s Numeric view.
In this view, the functions that
you have defined are
displayed in tabular format.
See “About the numeric
view” on page 2-16 for
further information.
Plot-Table view The VIEWS menu contains the Plot-Table view.
Select Plot-Table
Splits the screen into the plot
and the data table. See
“Other views for scaling and
splitting the graph” on
page 2-13 for futher information.
Plot-Detail view The VIEWS menu contains the Plot-Detail view.
Select Plot-Detail
Splits the screen into the plot
and a close-up.
See “Other views for scaling and splitting the graph” on
page 2-13 for further information.
Overlay Plot
view
The VIEWS menu contains the Overlay Plot view.
Select Overlay Plot
Plots the current
expression(s) without erasing
any pre-existing plot(s).
See “Other views for scaling and splitting the graph” on
page 2-13 for further information.
hp40g+.book Page 17 Friday, December 9, 2005 1:03 AM
1-18 Getting started
Note view Press NOTE to display the aplet’s note view.
This note is transferred with
the aplet if it is sent to
another calculator or to a
PC. A note view contains text
to supplement an aplet.
See “Notes and sketches” on page 20-1 for further
information.
Sketch view Press SKETCH to display the aplet’s sketch view.
Displays pictures to
supplement an aplet.
See “Notes and sketches” on
page 20-1 for further
information.
Aplet view configuration
You use the SETUP keys ( , and
) to configure the aplet. For example, press
SETUP-PLOT ( ) to display the input form for
setting the aplet’s plot settings. Angle measure is
controlled using the
MODES view.
Plot Setup Press SETUP-PLOT.
Sets parameters to plot a
graph.
Numeric Setup Press SETUP-NUM. Sets
parameters for building a
table of numeric values.
Symbolic Setup This view is only available in
the Statistics aplet in
mode, where it plays an
important role in choosing
data models.
Press
SETUP-SYMB.
hp40g+.book Page 18 Friday, December 9, 2005 1:03 AM
Getting started 1-19
To change views Each view is a separate environment. To change a view,
select a different view by pressing , ,
keys or select a view from the VIEWS menu. To change
to HOME, press . You do not explicitly close the
current view, you just enter another one—like passing
from one room into another in a house. Data that you
enter is automatically saved as you enter it.
To save aplet
configuration
You can save an aplet configuration that you have used,
and transfer the aplet to other HP 40gs calculators. See
“Creating new aplets based on existing aplets” on
page 22-1.
Mathematical calculations
The most commonly used math operations are available
from the keyboard. Access to other math functions is via
the MATH menu ( ). You can also CAS for symbolic
calculations. See “Computer Algebra System (CAS)” on
page 14-1 for further information.
To access programming commands, press
CMDS.
See “Programming commands” on page 21-13 for
further information.
Where to start The home base for the calculator is the HOME view
( ). You can do all non-symbolic calculations here,
and you can access all operations. (Symbolic
calculations are done using CAS.)
Entering
expressions
In the HOME view, you enter an expression in the
same left-to-right order that you would write the
expression. This is called algebraic entry. (In CAS
you enter expressions using the Equation Writer,
explained in detail in Chapter 15, “Equation
Writer”.)
To enter functions, select the key or MATH menu item
for that function. You can also enter a function by
using the Alpha keys to spell out its name.
Press to evaluate the expression you have in
the edit line (where the blinking cursor is). An
expression can contain numbers, functions, and
variables.
hp40g+.book Page 19 Friday, December 9, 2005 1:03 AM
1-20 Getting started
Example Calculate :
Long results If the result is too long to fit on the display line, or if you
want to see an expression in textbook format, press
to highlight it and then press .
Negative
numbers
Type to start a negative number or to insert a
negative sign.
To raise a negative number to a power, enclose it in
parentheses. For example, (–5)
2
= 25, whereas –5
2
=
–25.
Scientific
notation
(powers of 10)
A number like or is written in
scientific notation, that is, in terms of powers of ten. This
is simpler to work with than 50000 or 0.000000321. To
enter numbers like these, use
EEX. (This is easier than
using 10 .)
Example Calculate
4
EEX
13
6
EEX
23 3 EEX
5
Explicit and
implicit
multiplication
Implied multiplication takes place when two operands
appear with no operator in between. If you enter AB, for
example, the result is A*B.
23
2
14 8
3
----------------------------
45()ln
23
14
8
3
45
510
4
× 3.21 10
7
×
410
13
×()610
23
×()
310
5
×
----------------------------------------------------
hp40g+.book Page 20 Friday, December 9, 2005 1:03 AM
Getting started 1-21
However, for clarity, it is better to include the
multiplication sign where you expect multiplication in an
expression. It is clearest to enter AB as A*B.
HINT
Implied multiplication will not always work as expected.
For example, entering A(B+4) will not give A*(B+4).
Instead an error message is displayed: “Invalid User
Function”. This is because the calculator interprets
A(B+4) as meaning ‘evaluate function A at the value
B+4’, and function A does not exist. When in doubt, insert
the * sign manually.
Parentheses You need to use parentheses to enclose arguments for
functions, such as SIN(45). You can omit the final
parenthesis at the end of an edit line. The calculator
inserts it automatically.
Parentheses are also important in specifying the order of
operation. Without parentheses, the HP 40gs calculates
according to the order of algebraic precedence (the next
topic). Following are some examples using parentheses.
Entering... Calculates...
45 π sin (45 + π)
45 π sin (45) + π
85 9
85 9
85 9×
85 9×
hp40g+.book Page 21 Friday, December 9, 2005 1:03 AM
1-22 Getting started
Algebraic
precedence
order of
evaluation
Functions within an expression are evaluated in the
following order of precedence. Functions with the same
precedence are evaluated in order from left to right.
1. Expressions within parentheses. Nested parentheses
are evaluated from inner to outer.
2. Prefix functions, such as SIN and LOG.
3. Postfix functions, such as !
4. Power function, ^, NTHROOT.
5. Negation, multiplication, and division.
6. Addition and subtraction.
7. AN D a nd N OT.
8. OR and XOR.
9. Left argument of | (where).
10.Equals, =.
Largest and
smallest
numbers
The smallest number the HP 40gs can represent is
1×10
–499
(1E–499). A smaller result is displayed as
zero. The largest number is 9.99999999999 × 10
499
(1E499). A greater result is displayed as this number.
Clearing
numbers
clears the character under the cursor. When the
cursor is positioned after the last character,
deletes the character to the left of the cursor, that is, it
performs the same as a backspace key.
CANCEL ( ) clears the edit line.
CLEAR clears all input and output in the
display, including the display history.
Using previous
results
The HOME display ( ) shows you four lines of
input/output history. An unlimited (except by memory)
number of previous lines can be displayed by scrolling.
You can retrieve and reuse any of these values or
expressions.
Output
Last output
Input
Last input
Edit line
hp40g+.book Page 22 Friday, December 9, 2005 1:03 AM
Getting started 1-23
When you highlight a previous input or result (by pressing
), the and menu labels appear.
To copy a previous
line
Highlight the line (press ) and press . The
number (or expression) is copied into the edit line.
To reuse the last
result
Press ANS (last answer) to put the last result from the
HOME display into an expression.
ANS is a variable that
is updated each time you press .
To repeat a
previous line
To repeat the very last line, just press . Otherwise,
highlight the line (press ) first, and then press .
The highlighted expression or number is re-entered. If the
previous line is an expression containing the
ANS, the
calculation is repeated iteratively.
Example See how
ANS retrieves and reuses the last result
(50), and updates
ANS (from 50 to 75 to 100).
50 25
You can use the last result as the first expression in the edit
line without pressing
ANS. Pressing , , , or
, (or other operators that require a preceding
argument) automatically enters
ANS before the operator.
You can reuse any other expression or value in the HOME
display by highlighting the expression (using the arrow
keys), then pressing . See “Using previous results”
on page 1-22 for more details.
The variable
ANS is different from the numbers in HOME’s
display history. A value in
ANS is stored internally with the
full precision of the calculated result, whereas the
displayed numbers match the display mode.
hp40g+.book Page 23 Friday, December 9, 2005 1:03 AM
1-24 Getting started
HINT
When you retrieve a number from ANS, you obtain the
result to its full precision. When you retrieve a number
from the HOME’s display history, you obtain exactly what
was displayed.
Pressing evaluates (or re-evaluates) the last input,
whereas pressing
ANS copies the last result (as ANS)
into the edit line.
Storing a value
in a variable
You can save an answer in a variable and use the
variable in later calculations. There are 27 variables
available for storing real values. These are A to Z and θ.
See Chapter 17, “Variables and memory management”
for more information on variables. For example:
1. Perform a calculation.
45 8 3
2. Store the result in the A variable.
A
3. Perform another calculation using the A variable.
95 2 A
hp40g+.book Page 24 Friday, December 9, 2005 1:03 AM
Getting started 1-25
Accessing the
display history
Pressing enables the highlight bar in the display
history. While the highlight bar is active, the following
menu and keyboard keys are very useful:
Clearing the
display history
It’s a good habit to clear the display history (
CLEAR) whenever you have finished working in HOME. It
saves calculator memory to clear the display history.
Remember that all your previous inputs and results are
saved until you clear them.
Using fractions
To work with fractions in HOME, you set the number
format to Fraction or Mixed Fraction, as follows:
Setting Fraction
mode
1. In HOME, open the HOME MODES input form.
MODES
Key Function
, Scrolls through the display history.
Copies the highlighted expression to
the position of the cursor in the edit line.
Displays the current expression in
standard mathematical form.
Deletes the highlighted expression from
the display history, unless there is a
cursor in the edit line.
CLEAR
Clears all lines of display history and
the edit line.
hp40g+.book Page 25 Friday, December 9, 2005 1:03 AM
1-26 Getting started
2. Select Number Format, press to display the
options, and highlight Fraction or Mixed
Fraction.
3. Press to select the Number Format option, then
move to the precision value field.
4. Enter the precision value that you want to use, and
press to set the precision. Press to return
to HOME.
See “Setting fraction precision” below for more
information.
Setting fraction
precision
The fraction precision setting determines the precision in
which the HP 40gs converts a decimal value to a fraction.
The greater the precision value that is set, the closer the
fraction is to the decimal value.
By choosing a precision of 1 you are saying that the
fraction only has to match 0.234 to at least 1 decimal
place (3/13 is 0.23076...).
The fractions used are found using the technique of
continued fractions.
When converting recurring decimals this can be
important. For example, at precision 6 the decimal
0.6666 becomes 3333/5000 (6666/10000) whereas
at precision 3, 0.6666 becomes 2/3, which is probably
what you would want.
For example, when converting .234 to a fraction, the
precision value has the following effect:
hp40g+.book Page 26 Friday, December 9, 2005 1:03 AM
Getting started 1-27
Precision set to 1:
Precision set to 2:
Precision set to 3:
Precision set to 4
Fraction
calculations
When entering fractions:
You use the key to separate the numerator part
and the denominator part of the fraction.
To enter a mixed fraction, for example, 1
1
/
2
, you
enter it in the format (1+
1
/
2
).
For example, to perform the following calculation:
3(2
3
/
4
+ 5
7
/
8
)
1. Set the Number format mode to Fraction or
Mixed Fraction and specify a precision value of
4.
In this example, we’ll select Fraction as our
format.)
MODES
Select
Fraction
4
hp40g+.book Page 27 Friday, December 9, 2005 1:03 AM
1-28 Getting started
2. Enter the calculation.
323
457
8
Note: Ensure you are in
the HOME view.
3. Evaluate the calculation.
Note that if you had
selected Mixed
Fraction instead of
Fraction as the
Number format, the answer would have been
expressed as 25+7/8.
Converting
decimals to
fractions
To convert a decimal value to a fraction:
1. Set the number format mode to Fraction or Mixed
Fraction.
2. Either retrieve the value from the History, or enter the
value on the command line.
3. Press to convert the number to a fraction.
When converting a decimal to a fraction, keep the
following points in mind:
When converting a recurring decimal to a fraction,
set the fraction precision to about 6, and ensure that
you include more than six decimal places in the
recurring decimal that you enter.
In this example, the
fraction precision is set
to 6. The top
calculation returns the
correct result. The
bottom one does not.
To convert an exact decimal to a fraction, set the
fraction precision to at least two more than the
number of decimal places in the decimal.
hp40g+.book Page 28 Friday, December 9, 2005 1:03 AM
Getting started 1-29
In this example, the
fraction precision is set
to 6.
Complex numbers
Complex results The HP 40gs can return a complex number as a result for
some math functions. A complex number appears as an
ordered pair (x, y), where x is the real part and y is the
imaginary part. For example, entering returns (0,1).
To enter complex
numbers
Enter the number in either of these forms, where x is the
real part, y is the imaginary part, and i is the imaginary
constant, :
(x, y) or
x + iy.
To enter i:
press
or
press , or keys to select Constant,
to move to the right column of the menu, to
select i, and .
Storing complex
numbers
There are 10 variables available for storing complex
numbers: Z0 to Z9. To store a complex number in a
variable:
Enter the complex number, press , enter the
variable to store the number in, and press .
45
Z 0
1
1
hp40g+.book Page 29 Friday, December 9, 2005 1:03 AM
1-30 Getting started
Catalogs and editors
The HP 40gs has several catalogs and editors. You use
them to create and manipulate objects. They access
features and stored values (numbers or text or other items)
that are independent of aplets.
A catalog lists items, which you can delete or
transmit, for example an aplet.
An editor lets you create or modify items and
numbers, for example a note or a matrix.
Catalog/Editor Contents
Aplet library
()
Aplets.
Sketch editor
( SKETCH)
Sketches and diagrams, See
Chapter 20, “Notes and
sketches”.
List (
LIST)
Lists. In HOME, lists are
enclosed in {}. See Chapter 19,
“Lists”.
Matrix (
MATRIX)
One- and two-dimensional
arrays. In HOME, arrays are
enclosed in []. See Chapter 18,
“Matrices”.
Notepad (
NOTEPAD)
Notes (short text entries). See
Chapter 20, “Notes and
sketches”.
Program (
PROGRM)
Programs that you create, or
associated with user-defined
aplets. See Chapter 21,
“Programming”.
Equation Writer
()
The editor used for creating
expressions and equations in
CAS. See Chapter 15,
“Equation Writer”.
hp40g+.book Page 30 Friday, December 9, 2005 1:03 AM
Aplets and their views 2-1
2
Aplets and their views
Aplet views
This section examines the options and functionality of the
three main views for the Function, Polar, Parametric, and
Sequence aplets: Symbolic, Plot, and Numeric views.
About the Symbolic view
The Symbolic view is the defining view for the Function,
Parametric, Polar, and Sequence aplets. The other views
are derived from the symbolic expression.
You can create up to 10 different definitions for each
Function, Parametric, Polar, and Sequence aplet. You
can graph any of the relations (in the same aplet)
simultaneously by selecting them.
Defining an expression (Symbolic view)
Choose the aplet from the Aplet Library.
Press or to
select an aplet.
The Function,
Parametric, Polar, and Sequence aplets start in the
Symbolic view.
If the highlight is on an existing expression, scroll to
an empty line—unless you don’t mind writing over the
expression—or, clear one line ( ) or all lines
(
CLEAR).
Expressions are selected (check marked) on entry. To
deselect an expression, press . All
selected
expressions are plotted.
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
2-2 Aplets and their views
For a Function
definition, enter
an expression to
define F(X). The
only independent
variable in the
expression is X.
For a
Parametric
definition, enter
a pair of
expressions to
define X(T) and
Y(T). The only
independent variable in the expressions is T.
For a Polar
definition, enter
an expression to
define R(θ). The
only independent
variable in the
expression is θ.
For a Sequence
definition, either
enter the first term,
or the first and
second terms, for U
(U1, or...U9, or
U0). Then define
the nth term of the sequence in terms of N or of
the prior terms, U(N–1) and/or U(N–2). The
expressions should produce real-valued
sequences with integer domains. Or define the
nth term as a non-recursive expression in terms of
n only. In this case, the calculator inserts the first
two terms based on the expression that you
define.
Note: You will have to enter the second term if the
hp40gs is unable to calculate it automatically.
Typically if Ux(N) depends on Ux(N–2) then you
must enter Ux(2).
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Aplets and their views 2-3
Evaluating expressions
In aplets In the Symbolic view, a variable is a symbol only, and
does not represent one specific value. To evaluate a
function in Symbolic view, press . If a function calls
another function, then resolves all references to
other functions in terms of their independent variable.
1. Choose the Function
aplet.
Select Function
2. Enter the expressions in the Function aplet’s Symbolic
view.
A
B
F1
F2
3. Highlight F3(X).
4. Press
Note how the values
for F1(X) and F2(X) are
substituted into F3(X).
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
2-4 Aplets and their views
In HOME You can also evaluate any expression in HOME by
entering it into the edit line and pressing .
For example, define F4 as below. In HOME, type
F4(9)and press . This evaluates the expression,
substituting 9 in place of X into F4.
SYMB view keys The following table details the menu keys that you use to
work with the Symbolic view.
Key Meaning
Copies the highlighted expression to
the edit line for editing. Press
when done.
Checks/unchecks the current
expression (or set of expressions).
Only checked expression(s) are
evaluated in the Plot and Numeric
views.
Enters the independent variable in the
Function aplet. Or, you can use the
key on the keyboard.
Enters the independent variable in the
Parametric aplet. Or, you can use the
key on the keyboard.
Enters the independent variable in the
Polar aplet. Or, you can use the
key on the keyboard.
Enters the independent variable in the
Sequence aplet. Or, you can use the
key on the keyboard.
Displays the current expression in text
book form.
Resolves all references to other
definitions in terms of variables and
evaluates all arithmetic expressions.
Displays a menu for entering variable
names or contents of variables.
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Aplets and their views 2-5
About the Plot view
After entering and selecting (check marking) the
expression in the Symbolic view, press . To adjust
the appearance of the graph or the interval that is
displayed, you can change the Plot view settings.
You can plot up to ten expressions at the same time.
Select the expressions you want to be plotted together.
Setting up the plot (Plot view setup)
Press SETUP-PLOT to define any of the settings
shown in the next two tables.
1. Highlight the field to edit.
If there is a number to enter, type it in and press
or .
If there is an option to choose, press ,
highlight your choice, and press or .
As a shortcut to , just highlight the field to
change and press to cycle through the
options.
If there is an option to select or deselect, press
to check or uncheck it.
2. Press to view more settings.
3. When done, press to view the new plot.
Displays the menu for entering math
operations.
CHARS Displays special characters. To enter
one, place the cursor on it and press
. To remain in the CHARS menu
and enter another special character,
press .
Deletes the highlighted expression or
the current character in the edit line.
CLEAR Deletes all expressions in the list or
clears the edit line.
Key Meaning (Continued)
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2-6 Aplets and their views
Plot view
settings
The plot view settings are:
Those items with space for a checkmark are settings you
can turn on or off. Press to display the second
page.
Field Meaning
XRNG, YRNG Specifies the minimum and
maximum horizontal (X) and
vertical (Y) values for the plotting
window.
RES For function plots: Resolution;
“Faster” plots in alternate pixel
columns; “Detail” plots in every
pixel column.
TRNG Parametric aplet: Specifies the t-
values (T) for the graph.
θRNG Polar aplet: Specifies the angle (θ)
value range for the graph.
NRNG Sequence aplet: Specifies the
index (N) values for the graph.
TSTEP For Parametric plots: the increment
for the independent variable.
θSTEP For Polar plots: the increment
value for the independent
variable.
SEQPLOT For Sequence aplet: Stairstep or
Cobweb types.
XTICK Horizontal spacing for tickmarks.
YTICK Vertical spacing for tickmarks.
Field Meaning
SIMULT If more than one relation is being
plotted, plots them simultaneously
(otherwise sequentially).
INV. CROSS Cursor crosshairs invert the status
of the pixels they cover.
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Aplets and their views 2-7
Reset plot
settings
To reset the default values for all plot settings, press
CLEAR in the Plot Setup view. To reset the default
value for a field, highlight the field, and press .
Exploring the graph
Plot view gives you a selection of keys and menu keys to
explore a graph further. The options vary from aplet to
aplet.
PLOT view keys The following table details the keys that you use to work
with the graph.
CONNECT Connect the plotted points. (The
Sequence aplet always connects
them.)
LABELS Label the axes with XRNG and
YRNG values.
AXES Draw the axes.
GRID Draw grid points using XTICK
and YTICK spacing.
Field Meaning (Continued)
Key Meaning
CLEAR Erases the plot and axes.
Offers additional pre-defined views
for splitting the screen and for scaling
(“zooming”) the axes.
Moves cursor to far left or far right.
Moves cursor between relations.
or Interrupts plotting.
Continues plotting if interrupted.
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2-8 Aplets and their views
Trace a graph You can trace along a function using the or key
which moves the cursor along the graph. The display also
shows the current coordinate position (x, y) of the cursor.
Trace mode and the coordinate display are automatically
set when a plot is drawn.
Note: Tracing might not appear to exactly follow your
plot if the resolution (in Plot Setup view) is set to Faster.
This is because RES: FASTER plots in only every other
column, whereas tracing always uses every column.
In Function and Sequence Aplets: You can also
scroll (move the cursor) left or right beyond the edge of
the display window in trace mode, giving you a view of
more of the plot.
To move between
relations
If there is more than one relation displayed, press or
to move between relations.
Turns menu-key labels on and off.
When the labels are off, pressing
turns them back on.
Pressing once displays the
full row of labels.
Pressing a second time
removes the row of labels to
display only the graph.
Pressing a third time
displays the coordinate mode.
Displays the ZOOM menu list.
Turns trace mode on/off. A white box
appears over the on .
Opens an input form for you to enter
an X (or T or N or θ) value. Enter the
value and press . The cursor jumps
to the point on the graph that you
entered.
Function aplet only: turns on menu list
for root-finding functions (see
“Analyse graph with FCN functions”
on page 3-4).
Displays the current, defining
expression. Press to restore the
menu.
Key Meaning (Continued)
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Aplets and their views 2-9
To jump directly to
a value
To jump straight to a value rather than using the Trace
function, use the menu key. Press , then enter
a value. Press to jump to the value.
To turn trace on/off If the menu labels are not displayed, press first.
Turn off trace mode by pressing .
Turn on trace mode by pressing .
To turn the coordinate display off, press .
Zoom within a
graph
One of the menu key options is . Zooming redraws
the plot on a larger or smaller scale. It is a shortcut for
changing the Plot Setup.
The Set Factors... option enables you to set the
factors by which you zoom in or zoom out, and whether
the zoom is centered about the cursor.
ZOOM options Press , select an option, and press . (If
is not displayed, press .) Not all options are
available in all aplets.
Option Meaning
Center Re-centers the plot around the
current position of the cursor without
changing the scale.
Box... Lets you draw a box to zoom in on.
See “Other views for scaling and
splitting the graph” on page 2-13.
In Divides horizontal and vertical
scales by the X-factor and Y-factor.
For instance, if zoom factors are 4,
then zooming in results in 1/4 as
many units depicted per pixel. (see
Set Factors...)
Out Multiplies horizontal and vertical
scales by the X-factor and Y-factor
(see Set Factors...).
X-Zoom In Divides horizontal scale only, using
X-factor.
X-Zoom Out Multiplies horizontal scale, using
X-factor.
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2-10 Aplets and their views
Y-Zoom In Divides vertical scale only, using
Y-factor.
Y-Zoom Out Multiplies vertical scale only, using
Y-factor.
Square Changes the vertical scale to match
the horizontal scale. (Use this after
doing a Box Zoom, X-Zoom, or
Y-Zoom.)
Set
Factors...
Sets the X-Zoom and Y-Zoom factors
for zooming in or zooming out.
Includes option to recenter the plot
before zooming.
Auto Scale Rescales the vertical axis so that the
display shows a representative
piece of the plot, for the supplied x
axis settings. (For Sequence and
Statistics aplets, autoscaling
rescales both axes.)
The autoscale process uses the first
selected function only to determine
the best scale to use.
Decimal Rescales both axes so each pixel =
0.1 units. Resets default values for
XRNG
(–6.5 to 6.5) and YRNG (–3.1 to
3.2). (Not in Sequence or Statistics
aplets.)
Integer Rescales horizontal axis only,
making each pixel =1 unit. (Not
available in Sequence or Statistics
aplets.)
Trig Rescales horizontal axis so
1 pixel = π/24 radians, 7.58, or
8
1
/
3
grads; rescales vertical axis
so
1 pixel = 0.1 unit.
(Not in Sequence or Statistics
aplets.)
Option Meaning (Continued)
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Aplets and their views 2-11
ZOOM examples The following screens show the effects of zooming options
on a plot of .
Plot of
Zoom In:
In
Un-zoom:
Un-zoom
Note: Press to move to
the bottom of the Zoom list.
Zoom Out:
Out
Now un-zoom.
X-Zoom In:
X-Zoom In
Now un-zoom.
X-Zoom Out:
X-Zoom Out
Now un-zoom.
Un-zoom Returns the display to the previous
zoom, or if there has been only one
zoom, un-zoom displays the graph
with the original plot settings.
Option Meaning (Continued)
3 xsin
3 xsin
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2-12 Aplets and their views
Y-Zoom In:
Y-Zoom In
Now un-zoom.
Y-Zoom Out:
Y-Zoom Out
Zoom Square:
Square
To box zoom The Box Zoom option lets you draw a box around the
area you want to zoom in on by selecting the endpoints
of one diagonal of the zoom rectangle.
1. If necessary, press to turn on the menu-key
labels.
2. Press and select Box...
3. Position the cursor on one corner of the rectangle.
Press .
4. Use the cursor keys
( , etc.) to drag to
the opposite corner.
5. Press to zoom in
on the boxed area.
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Aplets and their views 2-13
To set zoom factors 1. In the Plot view, press .
2. Press .
3. Select Set Factors... and press .
4. Enter the zoom factors. There is one zoom factor for
the horizontal scale (XZOOM) and one for the vertical
scale (YZOOM).
Zooming out multiplies the scale by the factor, so that
a greater scale distance appears on the screen.
Zooming in divides the scale by the factor, so that a
shorter scale distance appears on the screen.
Other views for scaling and splitting the graph
The preset viewing options menu ( ) contains
options for drawing the plot using certain pre-defined
configurations. This is a shortcut for changing Plot view
settings. For instance, if you have defined a trigonometric
function, then you could select Trig to plot your function
on a trigonometric scale. It also contains split-screen
options.
In certain aplets, for example those that you download
from the world wide web, the preset viewing options
menu can also contain options that relate to the aplet.
VIEWS menu
options
Press , select an option, and press .
Option Meaning
Plot-
Detail
Splits the screen into the plot and a
close-up.
Plot-Table Splits the screen into the plot and
the data table.
Overlay
Plot
Plots the current expression(s)
without erasing any pre-existing
plot(s).
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2-14 Aplets and their views
Split the screen The Plot-Detail view can give you two simultaneous views
of the plot.
1. Press . Select Plot-Detail and press .
The graph is plotted twice. You can now zoom in on
the right side.
2. Press
,
select the zoom method
and press or
. This zooms the
right side. Here is an
example of split screen with Zoom In.
The Plot menu keys are available as for the full
plot (for tracing, coordinate display, equation
display, and so on).
Auto Scale Rescales the vertical axis so that the
display shows a representative
piece of the plot, for the supplied x
axis settings. (For Sequence and
Statistics aplets, autoscaling
rescales both axes.)
The autoscale process uses the first
selected function only to determine
the best scale to use.
Decimal Rescales both axes so each pixel =
0.1 unit. Resets default values for
XRNG
(–6.5 to 6.5) and YRNG (–3.1 to
3.2). (Not in Sequence or Statistics
aplets.)
Integer Rescales horizontal axis only,
making each pixel=1 unit. (Not
available in Sequence or Statistics
aplets.)
Trig Rescales horizontal axis so
1 pixel=π/24 radian, 7.58, or
8
1
/
3
grads; rescales vertical axis so
1 pixel = 0.1 unit.
(Not in Sequence or Statistics
aplets.)
Option Meaning (Continued)
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Aplets and their views 2-15
moves the leftmost cursor to the
screen’s left edge and moves the
rightmost cursor to the screen’s right edge.
The menu key copies the right plot to the left
plot.
3. To un-split the screen, press . The left side takes
over the whole screen.
The Plot-Table view gives you two simultaneous views of
the plot.
1. Press . Select
Plot-Table and
press . The screen
displays the plot on the
left side and a table of
numbers on the right side.
2. To move up and down the table, use the and
cursor keys. These keys move the tra.ce point left or
right along the plot, and in the table, the
corresponding values are highlighted.
3. To move between functions, use the and
cursor keys to move the cursor from one graph to
another.
4. To return to a full Numeric (or Plot) view, press
(or ).
Overlay plots If you want to plot over an existing plot without erasing
that plot, then use Overlay Plot instead of
. Note that tracing follows only the current
functions from the current aplet.
Decimal scaling Decimal scaling is the default scaling. If you have
changed the scaling to Trig or Integer, you can change it
back with Decimal.
Integer scaling Integer scaling compresses the axes so that each pixel is
and the origin is near the screen center.
Trigonometric
scaling
Use trigonometric scaling whenever you are plotting an
expression that includes trigonometric functions.
Trigonometric plots are more likely to intersect the axis at
points factored by π.
11×
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2-16 Aplets and their views
About the numeric view
After entering and selecting
(check marking) the
expression or expressions
that you want to explore in
the Symbolic view, press
to view a table of
data values for the independent variable (X, T, θ, or N)
and dependent variables.
Setting up the table (Numeric view setup)
Press NUM to define
any of the table settings.
Use the Numeric Setup
input form to configure the
table.
1. Highlight the field to edit. Use the arrow keys to move
from field to field.
If there is a number to enter, type it in and press
or . To modify an existing number,
press .
If there is an option to choose, press ,
highlight your choice, and press or .
Shortcut: Press the key to copy values
from the Plot Setup into NUMSTART and
NUMSTEP. Effectively, the menu key allows
you to make the table match the pixel columns in
the graph view.
2. When done, press to view the table of
numbers.
Numeric view
settings
The following table details the fields on the Numeric
Setup input form.
Field Meaning
NUMSTART The independent variable’s
starting value.
NUMSTEP The size of the increment from
one independent variable value
to the next.
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Aplets and their views 2-17
Reset numeric
settings
To reset the default values for all table settings, press
CLEAR.
Exploring the table of numbers
NUM view
menu keys
The following table details the menu keys that you use to
work with the table of numbers.
NUMTYPE Type of numeric table: Automatic
or Build Your Own. To build your
own table, you must type each
independent value into the table
yourself.
NUMZOOM Allows you to zoom in or out on a
selected value of the independent
variable.
Field Meaning (Continued)
Key Meaning
Displays ZOOM menu list.
Toggles between two character
sizes.
Displays the defining function
expression for the highlighted
column. To cancel this display, press
.
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2-18 Aplets and their views
Zoom within a
table
Zooming redraws the table of numbers in greater or
lesser detail.
ZOOM options The following table lists the zoom options:
The display on the right is a Zoom In of the display on the
left. The ZOOM factor is 4.
HINT
To jump to an independent variable value in the table,
use the arrow keys to place the cursor in the independent
variable column, then enter the value to jump to.
Option Meaning
In Decreases the intervals for the
independent variable so a narrower
range is shown. Uses the NUMZOOM
factor in Numeric Setup.
Out Increases the intervals for the
independent variable so that a
wider range is shown. Uses the
NUMZOOM factor in Numeric Setup.
Decimal Changes intervals for the
independent variable to 0.1 units.
Starts at zero. (Shortcut to changing
NUMSTART and NUMSTEP.)
Integer Changes intervals for the
independent variable to 1 unit.
Starts at zero. (Shortcut to changing
NUMSTEP.)
Trig Changes intervals for independent
variable to π/24 radian or 7.5
degrees or 8
1
/
3
grads. Starts at
zero.
Un-zoom Returns the display to the previous
zoom.
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Aplets and their views 2-19
Automatic
recalculation
You can enter any new value in the X column. When you
press , the values for the dependent variables are
recalculated, and the entire table is regenerated with the
same interval between X values.
Building your own table of numbers
The default NUMTYPE is “Automatic”, which fills the table
with data for regular intervals of the independent (X, T, θ,
or N) variable. With the NUMTYPE option set to “Build
Your Own”, you fill the table yourself by typing in the
independent-variable values you want. The dependent
values are then calculated and displayed.
Build a table 1. Start with an expression defined (in Symbolic view) in
the aplet of your choice. Note: Function, Polar,
Parametric, and Sequence aplets only.
2. In the Numeric Setup ( NUM), choose
NUMTYPE: Build Your Own.
3. Open the Numeric view ( ).
4. Clear existing data in the table (
CLEAR).
5. Enter the independent values in the left-hand column.
Type in a number and press . You do not have
to enter them in order, because the function
can rearrange them. To insert a number between two
others, use .
Clear data Press CLEAR, to erase the data from a table.
F1 and F2
entries are
generated
automatically
You enter
numbers into
the X column
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2-20 Aplets and their views
“Build Your Own” menu keys
Example: plotting a circle
Plot the circle, x
2
+ y
2
= 9. First rearrange it to read
.
To plot both the positive and negative y values, you need
to define two equations as follows:
and
1. In the Function aplet, specify the functions.
Key Meaning
Puts the highlighted independent
value (X, T, θ, or N) into the edit
line. Pressing replaces
this variable with its current value.
Inserts a zero value at the position
of the highlight. Replace a zero
by typing the number you want
and pressing .
Sorts the independent variable
values into ascending or
descending order. Press
and select the ascending or
descending option from the
menu, and press .
Toggles between two character
sizes.
Displays the defining function
expression for the highlighted
column.
Deletes the highlighted row.
CLEAR
Clears all data from the table.
y 9 x
2
±=
y 9 x
2
= y 9 x
2
=
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Aplets and their views 2-21
Select
Function
9
9
2. Reset the graph setup to the default settings.
SETUP-PLOT
CLEAR
3. Plot the two functions
and hide the menu so
that you can see all the
circle.
4. Reset the numeric setup to the default settings.
SETUP-NUM
CLEAR
5. Display the functions in numeric form.
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hp40g+.book Page 22 Friday, December 9, 2005 1:03 AM
Function aplet 3-1
3
Function aplet
About the Function aplet
The Function aplet enables you to explore up to 10
real-valued, rectangular functions y in terms of x. For
example .
Once you have defined a function you can:
create graphs to find roots, intercepts, slope, signed
area, and extrema
create tables to evaluate functions at particular
values.
This chapter demonstrates the basic tools of the Function
aplet by stepping you through an example. See “Aplet
views” on page 2-1 for further information about the
functionality of the Symbolic, Numeric, and Plot views.
Getting started with the Function aplet
The following example involves two functions: a linear
function and a quadratic equation
.
Open the
Function aplet
1. Open the Function aplet.
Select Function
The Function aplet starts
in the Symbolic view.
The Symbolic view is the defining view for Function,
Parametric, Polar, and Sequence aplets. The other
views are derived from the symbolic expression.
y 2x 3+=
y 1 x=
yx3+()
2
2=
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3-2 Function aplet
Define the
expressions
2. There are 10 function definition fields on the Function
aplet’s Symbolic view screen. They are labeled F1(X)
to F0(X). Highlight the function definition field you
want to use, and enter an expression. (You can press
to delete an existing line, or CLEAR to
clear all lines.)
1
3
2
Set up the plot You can change the scales of the x and y axes, graph
resolution, and the spacing of the axis ticks.
3. Display plot settings.
SETUP-PLOT
Note: For our example, you can leave the plot
settings at their default values since we will be using
the Auto Scale feature to choose an appropriate y
axis for our x axis settings. If your settings do not
match this example, press
CLEAR to restore the
default values.
4. Specify a grid for the graph.
Plot the
functions
5. Plot the functions.
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Function aplet 3-3
Change the
scale
6. You can change the scale to see more or less of your
graphs. In this example, choose Auto Scale. (See
“VIEWS menu options” on page 2-13 for a
description of Auto Scale).
Select Auto
Scale
Trace a graph 7. Trace the linear function.
6 times
Note: By default, the
tracer is active.
8. Jump from the linear function to the quadratic
function.
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3-4 Function aplet
Analyse graph
with FCN
functions
9. Display the Plot view menu.
From the Plot view menu, you can use the functions
on the FCN menu to find roots, intersections, slopes,
and areas for a function defined in the Function aplet
(and any Function-based aplets). The FCN functions
act on the currently selected graph. See “FCN
functions” on page 3-10 for further information.
To find a root of the
quadratic function
10.Move the cursor to the graph of the quadratic
equation by pressing the or key. Then move
the cursor so that it is near by pressing the
or key.
Select
Root
The root value is
displayed at the
bottom of the screen.
Note: If there is more
than one root (as in our
example), the
coordinates of the root closest to the current cursor
position are displayed.
To find the
intersection of the
two functions
11.Find the intersection of the two functions.
x 1=
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Function aplet 3-5
12.Choose the linear function whose intersection with the
quadratic function you wish to find.
The coordinates of the
intersection point are
displayed at the
bottom of the screen.
Note: If there is more
than one intersection
(as in our example), the coordinates of the
intersection point closest to the current cursor position
are displayed.
To find the slope of
the quadratic
function
13.Find the slope of the quadratic function at the
intersection point.
Select Slope
The slope value is
displayed at the
bottom of the screen.
To find the signed
area of the two
functions
14.To find the area between the two functions in the
range –2 x –1, first move the cursor to
and select the signed area option.
Select Signed area
15.Move the cursor to x = –2 by pressing the or
key.
F1 x() 1 x=
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3-6 Function aplet
16.Press to accept using F2(x) = (x + 3)
2
– 2 as the
other boundary for the integral.
17. Choose the end value
for x.
1
The cursor jumps to
x = –1 on the linear
function.
18.Display the numerical
value of the integral.
Note: See “Shading
area” on page 3-11
for another method of
calculating area.
To find the
extremum of the
quadratic
19.Move the cursor to the quadratic equation and find
the extremum of the quadratic.
Select Extremum
The coordinates of the
extremum are
displayed at the
bottom of the screen.
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Function aplet 3-7
HINT
The Root and Extremum functions return one value only
even if the function has more than one root or extremum.
The function finds the value closest to the position of the
cursor. You need to re-locate the cursor to find other roots
or extrema that may exist.
Display the
numeric view
20.Display the numeric view.
Set up the table 21.Display the numeric setup.
SETUP-NUM
See “Setting up the table (Numeric view setup)” on
page 2-16 for more information.
22.Match the table settings to the pixel columns in the
graph view.
Explore the
table
23.Display the table of values.
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3-8 Function aplet
To navigate around
a table
24.Move to X = –5.9.
6 times
To go directly to a
value
25.Move directly to X = 10.
1 0
To access the zoom
options
26.Zoom in on X = 10 by a factor of 4. Note: NUMZOOM
has a setting of 4.
In
To change font size 27. Display table numbers in large font.
To display the
symbolic definition
of a column
28.Display the symbolic definition for the F1 column.
The symbolic definition of
F1 is displayed at the
bottom of the screen.
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
Function aplet 3-9
Function aplet interactive analysis
From the Plot view ( ), you can use the functions on
the FCN menu to find roots, intersections, slopes, and
areas for a function defined in the Function aplet (and any
Function-based aplets). See “FCN functions” on page 3-
10. The FCN operations act on the currently selected
graph.
The results of the FCN functions are saved in the following
variables:
Area
Extremum
Isect
Root
Slope
For example, if you use the Root function to find the root
of a plot, you can use the result in calculations in HOME.
Access FCN
variables
The FCN variables are contained on the VARS menu.
To access FCN variables in HOME:
Select Plot FCN
or to choose a
variable
To access FCN variable in the Function aplet’s Symbolic
view:
Select Plot FCN
or to choose a variable
hp40g+.book Page 9 Friday, December 9, 2005 1:03 AM
3-10 Function aplet
FCN functions The FCN functions are:
Function Description
Root Select Root to find the root of the
current function nearest the
cursor. If no root is found, but only
an extremum, then the result is
labeled EXTR: instead of ROOT:.
(The root-finder is also used in the
Solve aplet. See also “Interpreting
results” on page 7-6.) The cursor
is moved to the root value on the
x-axis and the resulting x-value is
saved in a variable named
ROOT.
Extremum Select Extremum to find the
maximum or minimum of the
current function nearest the
cursor. This displays the
coordinate values and moves the
cursor to the extremum. The
resulting value is saved in a
variable named EXTREMUM.
Slope Select Slope to find the numeric
derivative at the current position
of the cursor. The result is saved in
a variable named SLOPE.
Signed area Select Signed area to find the
numeric integral. (If there are two
or more expressions
checkmarked, then you will be
asked to choose the second
expression from a list that
includes the x-axis.) Select a
starting point, then move the
cursor to selection ending point.
The result is saved in a variable
named AREA.
hp40g+.book Page 10 Friday, December 9, 2005 1:03 AM
Function aplet 3-11
Shading area You can shade a selected area between functions. This
process also gives you an approximate measurement of
the area shaded.
1. Open the Function aplet. The Function aplet opens in
the Symbolic view.
2. Select the expressions whose curves you want to
study.
3. Press to plot the functions.
4. Press or to position the cursor at the starting
point of the area you want to shade.
5. Press .
6. Press , then select Signed area and press
.
7. Press , choose the function that will act as the
boundary of the shaded area, and press .
8. Press the or key to shade in the area.
9. Press to calculate the area. The area
measurement is displayed near the bottom of the
screen.
To remove the shading, press to re-draw the plot.
Intersection Select Intersection to find the
intersection of two graphs nearest
the cursor. (You need to have at
least two selected expressions in
Symbolic view.) Displays the
coordinate values and moves the
cursor to the intersection. (Uses
Solve function.) The resulting x-
value is saved in a variable
named ISECT.
Function Description (Continued)
hp40g+.book Page 11 Friday, December 9, 2005 1:03 AM
3-12 Function aplet
Plotting a piecewise-defined function
Suppose you wanted to plot the following piecewise-
defined function.
1. Open the Function
aplet.
Select
Function
2. Highlight the line you want to use, and enter the
expression. (You can press to delete an existing
line, or
CLEAR to clear all lines.)
2
CHARS
1
CHARS > 1
AND CHARS 1
4
CHARS > 1
Note: You can use the menu key to assist in the
entry of equations. It has the same effect as pressing
.
fx()
x 2 x 1;+
x
2
1 x 1<;
4 xx1;
=
hp40g+.book Page 12 Friday, December 9, 2005 1:03 AM
Parametric aplet 4-1
4
Parametric aplet
About the Parametric aplet
The Parametric aplet allows you to explore parametric
equations. These are equations in which both x and y are
defined as functions of t. They take the forms
and .
Getting started with the Parametric aplet
The following example uses the parametric equations
Note: This example will produce a circle. For this
example to work, the angle measure must be set to
degrees.
Open the
Parametric aplet
1. Open the Parametric aplet.
Select
Parametric
Define the
expressions
2. Define the expressions.
3
3
xft()=
ygt()=
xt() 3 t
yt() 3 tcos=
sin=
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
4-2 Parametric aplet
Set angle
measure
3. Set the angle measure to degrees.
MODES
Select Degrees
Set up the plot 4. Display the graphing options.
PLOT
The Plot Setup input form has two fields not included
in the Function aplet, TRNG and TSTEP. TRNG
specifies the range of t values. TSTEP specifies the
step value between t values.
5. Set the TRNG and TSTEP so that t steps from 0° to
360° in 5° steps.
360
5
Plot the
expression
6. Plot the expression.
7. To see all the circle, press twice.
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Parametric aplet 4-3
Overlay plot 8. Plot a triangle graph over the existing circle graph.
PLOT
120
Select Overlay Plot
A triangle is displayed
rather than a circle (without changing the equation)
because the changed value of TSTEP ensures that
points being plotted are 120° apart instead of nearly
continuous.
You are able to explore the graph using trace, zoom,
split screen, and scaling functionality available in the
Function aplet. See “Exploring the graph” on page 2-
7 for further information.
Display the
numbers
9. Display the table of values.
You can highlight a
t-value, type in a
replacement value,
and see the table jump
to that value. You can also zoom in or zoom out on
any t-value in the table.
You are able to explore the table using ,
, build your own table, and split screen
functionality available in the Function aplet. See
“Exploring the table of numbers” on page 2-17 for
further information.
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hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Polar aplet 5-1
5
Polar aplet
Getting started with the Polar aplet
Open the Polar
aplet
1. Open the Polar aplet.
Select Polar
Like the Function aplet,
the Polar aplet opens
in the Symbolic view.
Define the
expression
2. Define the polar equation .
2 π
2
Specify plot
settings
3. Specify the plot settings. In this example, we will use
the default settings, except for the θRNG fields.
SETUP-PLOT
CLEAR
4 π
Plot the
expression
4. Plot the expression.
r 2πθ2()θ()
2
coscos=
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
5-2 Polar aplet
Explore the
graph
5. Display the Plot view menu key labels.
The Plot view options
available are the same
as those found in the
Function aplet. See
“Exploring the graph
on page 2-7 for further information.
Display the
numbers
6. Display the table of values for θ and R1.
The Numeric view
options available are
the same as those
found in the Function
aplet. See “Exploring the table of numbers” on
page 2-17 for further information.
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Sequence aplet 6-1
6
Sequence aplet
About the Sequence aplet
The Sequence aplet allows you to explore sequences.
You can define a sequence named, for example, U1:
in terms of n
in terms of U1(n–1)
•in terms of U1(n–2)
in terms of another sequence, for example, U2(n)
in any combination of the above.
The Sequence aplet allows you to create two types of
graphs:
A Stairsteps graph plots n on the horizontal
axis and U
n
on the vertical axis.
A Cobweb graph plots U
n–1
on the horizontal
axis and U
n
on the vertical axis.
Getting started with the Sequence aplet
The following example defines and then plots an
expression in the Sequence aplet. The sequence
illustrated is the well-known Fibonacci sequence where
each term, from the third term on, is the sum of the
preceding two terms. In this example, we specify three
sequence fields: the first term, the second term and a rule
for generating all subsequent terms.
However, you can also define a sequence by specifying
just the first term and the rule for generating all
subsequent terms. You will, though,have to enter the
second term if the hp40gs is unable to calculate it
automatically. Typically if the nth term in the sequence
depends on n2, then you must enter the second term.
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
6-2 Sequence aplet
Open the
Sequence aplet
1. Open the Sequence aplet.
Select
Sequence
The Sequence aplet
starts in the Symbolic
view.
Define the
expression
2. Define the Fibonacci sequence, in which each term
(after the first two) is the sum of the preceding two
terms:
, , for .
In the Symbolic view of the Sequence aplet, highlight
the U
1(1) field and begin defining your sequence.
1 1
Note: You can use the
, , ,
, and menu keys to assist in the entry of
equations.
Specify plot
settings
3. In Plot Setup, first set the SEQPLOT option to
Stairstep. Reset the default plot settings by
clearing the Plot Setup view.
SETUP-PLOT
CLEAR
8
8
U
1
1= U
2
1=
U
n
U
n 1
U
n
2
+= n 3>
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Sequence aplet 6-3
Plot the
sequence
4. Plot the Fibonacci
sequence.
5. In Plot Setup, set the SEQPLOT option to Cobweb.
SETUP-PLOT
Select Cobweb
Display the table 6. Display the table of values for this example.
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Solve aplet 7-1
7
Solve aplet
About the Solve aplet
The Solve aplet solves an equation or an expression for
its unknown variable. You define an equation or
expression in the symbolic view, then supply values for all
the variables except one in the numeric view. Solve works
only with real numbers.
Note the differences between an equation and an
expression:
An equation contains an equals sign. Its solution is a
value for the unknown variable that makes both sides
have the same value.
An expression does not contain an equals sign. Its
solution is a root, a value for the unknown variable
that makes the expression have a value of zero.
You can use the Solve aplet to solve an equation for any
one of its variables.
When the Solve aplet is started, it opens in the Solve
Symbolic view.
In Symbolic view, you specify the expression or
equation to solve. You can define up to ten equations
(or expressions), named E0 to E9. Each equation can
contain up to 27 real variables, named A to Z and θ.
In Numeric view, you specify the values of the known
variables, highlight the variable that you want to
solve for, and press .
You can solve the equation as many times as you want,
using new values for the knowns and highlighting a
different unknown.
Note: It is not possible to solve for more than one variable
at once. Simultaneous linear equations, for example,
should be solved using the Linear Solver aplet,matrices or
graphs in the Function aplet.
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
7-2 Solve aplet
Getting started with the Solve aplet
Suppose you want to find the acceleration needed to
increase the speed of a car from 16.67 m/sec (60 kph)
to 27.78 m/sec (100 kph) in a distance of 100 m.
The equation to solve is:
Open the Solve
aplet
1. Open the Solve aplet.
Select Solve
The Solve aplet starts in
the symbolic view.
Define the
equation
2. Define the equation.
V
U
2
A
D
Note: You can use the menu key to assist in the
entry of equations.
Enter known
variables
3. Display the Solve numeric view screen.
V
2
U
2
2A
D
+=
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Solve aplet 7-3
4. Enter the values for the known variables.
2 7 7 8
1 6 6 7
1 0 0
HINT
If the Decimal Mark setting in the Modes input form
( MODES) is set to Comma, use instead of .
Solve the
unknown
variable
5. Solve for the unknown variable (A).
Therefore, the acceleration needed to increase the
speed of a car from 16.67 m/sec (60 kph) to 27.78
m/sec
(100 kph) in a distance of 100 m is approximately
2.47 m/s
2
.
Because the variable A in the equation is linear we
know that we need not look for any other solutions.
Plot the
equation
The Plot view shows one graph for each side of the
selected equation. You can choose any of the
variables to be the independent variable.
The current equation is .
One of these is , with , that is,
. This graph will be a horizontal line.
The other graph will be , with
and , that is,
. This graph is also a line. The
desired solution is the value of A where these two
lines intersect.
V
2
U
2
2A
D
+=
YV
2
= V 27.78=
Y 771.7284=
Y
U
2
2A
D
+=
U 16.67= D 100=
Y 200A 277.8889+=
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
7-4 Solve aplet
6. Plot the equation for variable A.
Select Auto
Scale
7. Trace along the graph
representing the left
side of the equation
until the cursor nears
the intersection.
20 times
Note the value of A displayed near the bottom left
corner of the screen.
The Plot view provides a convenient way to find an
approximation to a solution instead of using the
Numeric view Solve option. See “Plotting to find
guesses” on page 7-7 for more information.
Solve aplet’s NUM view keys
The Solve aplet’s NUM view keys are:
Key Meaning
Copies the highlighted value to the
edit line for editing. Press when
done.
Displays a message about the
solution (see “Interpreting results” on
page 7-6).
Displays other pages of variables, if
any.
Displays the symbolic definition of the
current expression. Press when
done.
Finds a solution for the highlighted
variable, based on the values of the
other variables.
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Solve aplet 7-5
Use an initial guess
You can usually obtain a faster and more accurate
solution if you supply an estimated value for the unknown
variable before pressing . Solve starts looking for
a solution at the initial guess.
Before plotting, make sure the unknown variable is
highlighted in the numeric view. Plot the equation to help
you select an initial guess when you don’t know the range
in which to look for the solution. See “Plotting to find
guesses” on page 7-7 for further information.
HINT
An initial guess is especially important in the case of a
curve that could have more than one solution. In this case,
only the solution closest to the initial guess is returned.
Number format You can change the number format for the Solve aplet in
the Numeric Setup view. The options are the same as in
HOME MODES: Standard, Fixed, Scientific,
Engineering, Fraction and Mixed Fraction. For all except
Standard, you also specify how many digits of accuracy
you want. See “Mode settings” on page 1-10 for more
information.
You might find it handy to set a different number format
for the Solve aplet if, for example, you define equations
to solve for the value of money. A number format of
Fixed 2 would be appropriate in this case.
Clears highlighted variable to zero or
deletes current character in edit line,
if edit line is active.
CLEAR Resets all variable values to zero or
clears the edit line, if cursor is in edit
line.
Key Meaning (Continued)
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
7-6 Solve aplet
Interpreting results
After Solve has returned a solution, press in the
Numeric view for more information. You will see one of
the following three messages. Press to clear the
message.
Message Condition
Zero The Solve aplet found a point where
both sides of the equation were
equal, or where the expression was
zero (a root), within the calculator's
12-digit accuracy.
Sign Reversal Solve found two points where the
difference between the two sides of
the equation has opposite signs, but
it cannot find a point in between
where the value is zero. Similarly,
for an expression, where the value
of the expression has different signs
but is not precisely zero. This might
be because either the two points are
neighbours (they differ by one in the
twelfth digit), or the equation is not
real-valued between the two points.
Solve returns the point where the
value or difference is closer to zero.
If the equation or expression is
continuously real, this point is
Solve’s best approximation of an
actual solution.
Extremum Solve found a point where the value
of the expression approximates a
local minimum (for positive values)
or maximum (for negative values).
This point may or may not be a
solution.
Or: Solve stopped searching at
9.99999999999E499, the largest
number the calculator can
represent.
Note that the value returned is
probably not valid.
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
Solve aplet 7-7
If Solve could not find a solution, you will see one of the
following two messages.
HINT
It is important to check the information relating to the
solve process. For example, the solution that the Solve
aplet finds is not a solution, but the closest that the
function gets to zero. Only by checking the information
will you know that this is the case.
The Root-Finder
at work
You can watch the process of the root-finder calculating
and searching for a root. Immediately after pressing
to start the root-finder, press any key except .
You will see two intermediate guesses and, to the left, the
sign of the expression evaluated at each guess. For
example:
+ 2 2.219330555745
– 1 21.31111111149
You can watch as the root-finder either finds a sign
reversal or converges on a local extrema or does not
converge at all. If there is no convergence in process, you
might want to cancel the operation (press ) and start
over with a different initial guess.
Plotting to find guesses
The main reason for plotting in the Solve aplet is to help
you find initial guesses and solutions for those equations
that have difficult-to-find or multiple solutions.
Consider the equation of motion for an accelerating
body:
Message Condition
Bad Guess(es) The initial guess lies outside the
domain of the equation.
Therefore, the solution was not a
real number or it caused an error.
Constant? The value of the equation is the
same at every point sampled.
2
2
0
AT
TVX +=
hp40g+.book Page 7 Friday, December 9, 2005 1:03 AM
7-8 Solve aplet
where X is distance, V
0
is initial velocity, T is time, and A
is acceleration. This is actually two equations, Y = X and
Y = V
0
T + (AT
2
) / 2.
Since this equation is quadratic for T, there can be both
a positive and a negative solution. However, we are
concerned only with positive solutions, since only positive
distance makes sense.
1. Select the Solve aplet and enter the equation.
Select Solve
X
V
T
A
T 2
2. Find the solution for T (time) when X=30, V=2, and
A=4. Enter the values for X, V, and A; then highlight
the independent variable, T.
30
2
4
to highlight T
3. Use the Plot view to find an initial guess for T. First set
appropriate X and Y ranges in the Plot Setup. With
equation X = V x T + A x T
2
/2, the plot will produce
two graphs: one for and one for
X = V x T + A x T
2
/2. Since we have set in
this example, one of the graphs will be .
Therefore, make the YRNG5 to 35. Keep the XRNG
default of – 6.5 to 6.5.
SETUP-PLOT
5 35
4. Plot the graph.
YX=
X 30=
Y 30=
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
Solve aplet 7-9
5. Move the cursor near the positive (right-side)
intersection. This cursor value will be an initial guess
for T.
Press until the
cursor is at the
intersection.
The two points of
intersection show that
there are two solutions for this equation. However,
only positive values for X make sense, so we want to
find the solution for the intersection on the right side
of the y-axis.
6. Return to the Numeric
view.
Note: the T-value is filled in with the position of the
cursor from the Plot view.
7. Ensure that the T value is highlighted, and solve the
equation.
Use this equation to solve for another variable, such as
velocity. How fast must a body’s initial velocity be in
order for it to travel 50 m within 3 seconds? Assume the
same acceleration, 4 m/s
2
. Leave the last value of V as
the initial guess.
3
50
hp40g+.book Page 9 Friday, December 9, 2005 1:03 AM
7-10 Solve aplet
Using variables in equations
You can use any of the real variable names, A to Z and
θ. Do not use variable names defined for other types,
such as M1 (a matrix variable).
Home variables All home variables (other than those for aplet settings, like
Xmin and Ytick) are global, which means they are
shared throughout the different aplets of the calculator. A
value that is assigned to a home variable anywhere
remains with that variable wherever its name is used.
Therefore, if you have defined a value for T (as in the
above example) in another aplet or even another Solve
equation, that value shows up in the Numeric view for this
Solve equation. When you then redefine the value for T
in this Solve equation, that value is applied to T in all
other contexts (until it is changed again).
This sharing allows you to work on the same problem in
different places (such as HOME and the Solve aplet)
without having to update the value whenever it is
recalculated.
HINT
As the Solve aplet uses existing variable values, be sure
to check for existing variable values that may affect the
solve process. (You can use
CLEAR to reset all
values to zero in the Solve aplet’s Numeric view if you
wish.)
Aplet variables Functions defined in other aplets can also be referenced
in the Solve aplet. For example, if, in the Function aplet,
you define F1(X)=X
2
+10, you can enter F1(X)=50 in
the Solve aplet to solve the equation X
2
+10=50.
hp40g+.book Page 10 Friday, December 9, 2005 1:03 AM
Linear Solver aplet 8-1
8
Linear Solver aplet
About the Linear Solver aplet
The Linear Solver aplet allows you to solve a set of linear
equations. The set can contain two or three linear
equations.
In a two-equation set, each equation must be in the form
. In a three-equation set, each equation must
be in the form .
You provide values for a, b, and k (and c in three-
equation sets) for each equation, and the Linear Solver
aplet will attempt to solve for x and y (and z in three-
equation sets).
The hp40gs will alert you if no solution can be found, or
if there is an infinite number of solutions.
Note that the Linear Solver aplet only has a numeric view.
Getting started with the Linear Solver aplet
The following example defines a set of three equations
and then solves for the unknown variables.
Open the
Linear Solver
aplet
1. Open the Linear Sequence aplet.
Select Linear
Solver
The Linear Equation
Solver opens.
Choose the
equation set
2. If the last time you used
the Linear Solver aplet
you solved for two
equations, the two-
equation input form is
displayed (as in the
ax by+ k=
ax by cz++ k=
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
8-2 Linear Solver aplet
example in the previous step). To solve a three-
equation set, press . Now the input form
displays three equations.
If the three-equation input form is displayed and you want
to solve a two-equation set, press .
In this example, we are going to solve the following
equation set:
Hence we need the three-equation input form.
Define and
solve the
equations
3. You define the equations you want to solve by
entering the co-efficients of each variable in each
equation and the constant term. Notice that the cursor
is immediately positioned at the co-efficient of x in the
first equation. Enter that co-efficient and press or
.
4. The cursor moves to the next co-efficient. Enter that co-
efficient, press or , and continue doing
likewise until you have defined all the equations.
Note: you can enter the name of a variable for any
co-efficient or constant. Press and begin
entering the name. The menu key appears.
Press that key to lock alphabetic entry mode. Press it
again to cancel the lock.
Once you have entered
enough values for the
solver to be able to
generate solutions,
those solutions appear
on the display. In the
example at the right,
the solver was able to find solutions for x, y, and z as
soon as the first co-efficient of the last equation was
entered.
6x 9y 6z++ 5=
7x 10y 8z++ 10=
6x 4y+6=
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Linear Solver aplet 8-3
As you enter each of
the remaining known
values, the solution
changes. The example
at the right shows the
final solution once all
the co-efficients and
constants are entered for the set of equations we set
out to solve.
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Triangle Solve aplet 9-1
9
Triangle Solve aplet
About the Triangle Solver aplet
The Triangle Solver aplet allows you to determine the
length of a side of a triangle, or the angle at the vertex of
a triangle, from information you supply about the other
lengths and/or other angles.
You need to specify at least three of the six possible
values—the lengths of the three sides and the size of the
three angles—before the solver can calculate the other
values. Moreover, at least one value you specify must be
a length. For example, you could specify the lengths of
two sides and one of the angles; or you could specify two
angles and one length; or all three lengths. In each case,
the solver will calculate the remaining lengths or angles.
The HP 40gs will alert you if no solution can be found, or
if you have provided insufficient data.
If you are determining the properties of a right-angled
triangle, a simpler input form is available by pressing the
menu key.
Note that the Triangle Solver aplet only has a numeric
view.
Getting started with the Triangle Solver aplet
The following example solves for the unknown length of
the side of a triangle whose two known sides—of lengths
4 and 6—meet at an angle of 30 degrees.
Before you begin: You should make sure that your angle
measure mode is appropriate. If the angle information
you have is in degrees (as in this example) and your
current angle measure mode is radians or grads, change
the mode to degrees before running the solver. (See
“Mode settings” on page 1-10 for instructions.) Because
the angle measure mode is associated with the aplet, you
should start the aplet first and then change the setting.
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
9-2 Triangle Solve aplet
Open the
Triangle
Solver aplet
1. Open the Triangle Solver aplet.
Select
Triangle Solver
The Triangle Solver
aplet opens.
Note: if you have already used the Triangle Solver,
the entries and results from the previous use will still
be displayed. To start the Triangle Solver afresh, clear
the previous entries and results by pressing
CLEAR.
Choose the
triangle type
2. If the last time you used
the Triangle Solver
aplet you used the
right-angled triangle
input form, that input
form is displayed
again (as in the
example at the right). If the triangle you are
investigating is not a right-angled triangle, or you are
not sure what type it is, you should use the general
input form (illustrated in the previous step). To switch
to the general input form, press .
If the general input form is displayed and you are
investigating a right-angled triangle, press to
display the simpler input form.
Specify the
known values
3. Using the arrow keys, move to a field whose value
you know, enter the value and press or .
Repeat for each known value.
Note that the lengths of
the sides are labeled
A, B, and C, and the
angles are labeled
α
,
β
, and
δ
. It is important
that you enter the
known values in the
appropriate fields. In our example, we know the
length of two sides and the angle at which those
sides meet. Hence if we specify the lengths of sides A
and B, we must enter the angle as
δ
(since
δ
is the
angle where A and B meet). If instead we entered the
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Triangle Solve aplet 9-3
lengths as B and C, we would need to specify the
angle as
α
. The illustration on the display will help
you determine where to enter the known values.
Note: if you need to change the angle neasure mode,
press MODES, change the mode, and then
press to return to the aplet.
4. Press . The solver
calculates the values of
the unknown variables
and displays. As the
illustration at the right
shows, the length of
the unknown side in our example is 3.2296. (The
other two angles have also been calculated.)
Note: if two sides and
an adjacent acute
angle are entered and
there are two solutions,
only one will be
displayed initially.
In this case, an
menu key is displayed
(as in this example).
You press to
display the second
solution, and
again to return to the
first solution.
Errors No solution with
given data
If you are using the general
input form and you enter
more than 3 values, the
values might not be
consistent, that is, no
triangle could possibly have all the values you specified.
In these cases, No sol with given data appears on
the screen.
The situation is similar if you are using the simpler input
form (for a right-angled triangle) and you enter more than
two values.
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
Not enough data
If you are using the general
input form, you need to
specify at least three values
for the Triangle Solver to
be able to calculate the
remaining attributes of the
triangle. If you specify less than three, Not enough
data appears on the screen.
If you are using the simplified input form (for a right-
angled triangle), you must specify at least two values.
In addition, you cannot specify only angles and no
lengths.
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Statistics aplet 10-1
10
Statistics aplet
About the Statistics aplet
The Statistics aplet can store up to ten data sets at one
time. It can perform one-variable or two-variable
statistical analysis of one or more sets of data.
The Statistics aplet starts with the Numeric view which is
used to enter data. The Symbolic view is used to specify
which columns contain data and which column contains
frequencies.
You can also compute statistics values in HOME and
recall the values of specific statistics variables.
The values computed in the Statistics aplet are saved in
variables, and many of these variables are listed by the
function accessible from the Statistics aplet’s
Numeric view screen.
Getting started with the Statistics aplet
The following example asks you to enter and analyze the
advertising and sales data (in the table below), compute
statistics, fit a curve to the data, and predict the effect of
more advertising on sales.
Advertising minutes
(independent, x)
Resulting Sales ($)
(dependent, y)
21400
1 920
31100
52265
52890
42200
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10-2 Statistics aplet
Open the
Statistics aplet
1. Open the Statistics aplet and clear existing data by
pressing .
Select Statistics
The Statistics aplet
starts in the Numerical
view.
At any time the Statistics aplet is configured for only
one of two types of statistical explorations: one-
variable ( ) or two-variable ( ). The 5th
menu key label in the Numeric view toggles between
these two options and shows the current option.
2. Select .
You need to select because in this example
we are analyzing a dataset comprising two
variables: advertising minutes and resulting sales.
Enter data 3. Enter the data into the columns.
2 1
3 5
5 4
to move to the next
column
1400 920
1100 2265
2890 2200
1VAR/2VAR
menu key label
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Statistics aplet 10-3
Choose fit and
data columns
4. Select a fit in the Symbolic setup view.
SETUP-SYMB
Select Linear
You can create up to five explorations of two-variable
data, named S1 to S5. In this example, we will create
just one: S1.
5. Specify the columns that hold the data you want to
analyze.
You could have entered
your data into columns
other than C1 and C2.
Explore statistics 6. Find the mean advertising time (MEANX) and the
mean sales (MEANY).
MEANX is 3.3 minutes
and MEANY is about
$1796.
7. Scroll down to display the value for the correlation
coefficient (CORR). The CORR value indicates how
well the linear model fits the data.
9 times
The value is .8995.
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10-4 Statistics aplet
Setup plot 8. Change the plotting range to ensure all the data
points are plotted (and select a different point mark, if
you wish).
SETUP-PLOT
7
100
4000
Plot the graph 9. Plot the graph.
Draw the
regression curve
10.Draw the regression curve (a curve to fit the data
points).
This draws the
regression line for the
best linear fit.
Display the
equation for
best linear fit
11.Return to the Symbolic view.
12.Display the equation for the best linear fit.
to move to the
FIT1 field
The full FIT1
expression is shown.
The slope (m) is 425.875. The y-intercept (b) is
376.25.
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Statistics aplet 10-5
Predict values 13.To find the predicted sales figure if advertising were
to go up to 6 minutes:
S (to highlight
Stat-Two)
(to highlight
PREDY)
6
14.Return to the Plot view.
15.Jump to the indicated point on the regression line.
6
Observe the predicted
y-value in the left
bottom corner of the
screen.
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10-6 Statistics aplet
Entering and editing statistical data
The Numeric view ( ) is used to enter data into the
Statistics aplet. Each column represents a variable named
C0 to C9. After entering the data, you must define the
data set in the Symbolic view ( ).
HINT
A data column must have at least four data points to
provide valid two-variable statistics, or two data points
for one-variable statistics.
You can also store statistical data values by copying lists
from HOME into Statistics data columns. For example, in
HOME, L1 C1 stores a copy of the list L1 into the
data-column variable C1.
Statistics aplet’s NUM view keys
The Statistics aplet’s Numeric view keys are:
Key Meaning
Copies the highlighted item into the
edit line.
Inserts a zero value above the
highlighted cell.
Sorts the specified independent
data column in ascending or
descending order, and rearranges
a specified dependent (or
frequency) data column
accordingly.
Switches between larger and
smaller font sizes.
A toggle switch to select one-
variable or two-variable statistics.
This setting affects the statistical
calculations and plots. The label
indicates which setting is current.
Computes descriptive statistics for
each data set specified in Symbolic
view.
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Statistics aplet 10-7
Example You are measuring the height of students in a classroom
to find the mean height. The first five students have the
following measurements 160cm, 165cm, 170cm,
175cm, 180cm.
1. Open the Statistics aplet.
Select
Statistics
2. Enter the measurement
data.
160
165
170
175
180
Deletes the currently highlighted
value.
CLEAR Clears the current column or all
columns of data. Pregss
CLEAR to display a menu list,
then select the current column or all
columns option, and press .
cursor key
Moves to the first or last row, or first
or last column.
Key Meaning (Continued)
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10-8 Statistics aplet
3. Find the mean of the
sample.
Ensure the /
menu key label
reads .
Press
to see the
statistics calculated from the sample data in C1.
Note that the title of the
column of statistics is
H1. There are 5 data
set definitions available
for one-variable
statistics: H1–H5. If
data is entered in C1, H1 is automatically set to use
C1 for data, and the frequency of each data point is
set to 1. You can select other columns of data from
the Statistics Symbolic setup view.
4. Press to close the
statistics window and
press key to see
the data set definitions.
The first column
indicates the associated column of data for each data
set definition, and the second column indicates the
constant frequency, or the column that holds the
frequencies.
The keys you can use from this window are:
Key Meaning
Copies the column variable (or
variable expression) to the edit line
for editing. Press when done.
Checks/unchecks the current data
set. Only the checkmarked data
set(s) are computed and plotted.
or Typing aid for the column variables
( ) or for the Fit expressions ( ).
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Statistics aplet 10-9
To continue our example, suppose that the heights of the
rest of the students in the class are measured, but each
one is rounded to the nearest of the five values first
recorded. Instead of entering all the new data in C1, we
shall simply add another column, C2, that holds the
frequencies of our five data points in C1.
Displays the current variable
expression in standard
mathematical form. Press when
done.
Evaluates the variables in the
highlighted column (C1, etc.)
expression.
Displays the menu for entering
variable names or contents of
variables.
Displays the menu for entering math
operations.
Deletes the highlighted variable or
the current character in the edit line.
CLEAR Resets default specifications for the
data sets or clears the edit line (if it
was active).
Note: If
CLEAR is used the
data sets will need to be selected
again before re-use.
Key Meaning (Continued)
Height
(cm)
Frequency
160 5
165 3
170 8
175 2
180 1
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10-10 Statistics aplet
5. Move the highlight bar
into the right column of
the H1 definition and
replace the frequency
value of 1 with the
name C2.
2
6. Return to the numeric view.
7. Enter the frequency data shown in the above table.
5
3
8
2
1
8. Display the computed
statistics.
The mean height is
approximately
167.63cm.
9. Setup a histogram plot for the data.
SETUP-PLOT
Enter set up information
appropriate to your
data.
10.Plot a histogram of the data.
Save data The data that you enter is automatically saved. When you
are finished entering data values, you can press a key for
another Statistics view (like ), or you can switch to
another aplet or HOME.
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Statistics aplet 10-11
Edit a data set In the Numeric view of the Statistics aplet, highlight the
data value to change. Type a new value and
press , or press to copy the value to the edit
line for modification. Press after modifying the
value on the edit line.
Delete data To delete a single data item, highlight it and press
. The values below the deleted cell will scroll up
one row.
To delete a column of data, highlight an entry in that
column and press
CLEAR. Select the column
name.
To delete all columns of data, press CLEAR.
Select All columns.
Insert data Highlight the entry following the point of insertion. Press
, then enter a number. It will write over the zero that
was inserted.
Sort data
values
1. In Numeric view, highlight the column you want to
sort, and press .
2. Specify the Sort Order. You can choose either
Ascending or Descending.
3. Specify the INDEPENDENT and DEPENDENT data
columns. Sorting is by the independent column. For
instance, if Age is C1 and Income is C2 and you
want to sort by Income, then you make C2 the
independent column for the sorting and C1 the
dependent column.
To sort just one column, choose None for the
dependent column.
For one-variable statistics with two data columns,
specify the frequency column as the dependent
column.
4. Press .
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10-12 Statistics aplet
Defining a regression model
The Symbolic view includes an expression (Fit1 through
Fit5) that defines the regression model, or “fit”, to use for
the regression analysis of each two-variable data set.
There are three ways to select a regression model:
Accept the default option to fit the data to a straight
line.
Select one of the available fit options in Symbolic
Setup view.
Enter your own mathematical expression in Symbolic
view. This expression will be plotted, but it will not be
fitted to the data points.
Angle Setting You can ignore the angle measurement mode unless your
Fit definition (in Symbolic view) involves a trigonometric
function. In this case, you should specify in the mode
screen whether the trigonometric units are to be
interpreted in degrees, radians, or grads.
To choose the fit 1. In Numeric view, make sure is set.
2. Press
SETUP-SYMB to display the Symbolic Setup
view. Highlight the Fit number (S1FIT to S5FIT) you
want to define.
3. Press and select from the list. Press when
done. The regression formula for the fit is displayed in
Symbolic view.
Fit models Ten fit models are available:
Fit model Meaning
Linear (Default.) Fits the data to a
straight line, y = mx+b. Uses a
least-squares fit.
Logarithmic Fits to a logarithmic curve,
y = m lnx + b.
Exponential Fits to an exponential curve,
y = be
mx
.
Power Fits to a power curve, y = bx
m
.
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Statistics aplet 10-13
To define your
own fit
1. In Numeric view, make sure is set.
2. Display the Symbolic view.
3. Highlight the Fit expression (Fit1, etc.) for the
desired data set.
4. Type in an expression and press .
The independent variable must be X, and the
expression must not contain any unknown variables.
Example: .
This automatically changes the Fit type (S1FIT, etc.) in
the Symbolic Setup view to User Defined.
Quadratic Fits to a quadratic curve,
y = ax
2
+bx+c. Needs at least
three points.
Cubic Fits to a cubic curve,
y = ax
3
+bx
2
+cx+d. Needs at least
four points.
Logistic Fits to a logistic curve,
,
where L is the saturation value for
growth. You can store a positive
real value in L, or—if L=0—let L
be computed automatically.
Exponent Fits to an exponent curve,
.
Trigonometric Fits to a trigonometric curve,
. Needs
at least three points.
User Defined Define your own expression (in
Symbolic view.)
Fit model Meaning (Continued)
y
L
1 ae
bx()
+
--------------------------
=
yab
x
=
ya bxc+()sin d+=
1.5 xcos× 0.3 xsin×+
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10-14 Statistics aplet
Computed statistics
One-variable
When the data set contains an odd number of values, the
data set’s median value is not used when calculating Q1
and Q3 in the table above. For example, for the following
data set:
{3,5,7,8,15,16,17}
only the first three items, 3, 5, and 7 are used to calculate
Q1, and only the last three terms, 15, 16, and 17 are
used to calculate Q3.
Statistic Definition
NΣ Number of data points.
TOTΣ Sum of data values (with their
frequencies).
MEANΣ Mean value of data set.
PVARΣ Population variance of data set.
SVARΣ Sample variance of data set.
PSDEV Population standard deviation of
data set.
SSDEV Sample standard deviation of data
set.
MINΣ Minimum data value in data set.
Q1 First quartile: median of values to
left of median.
MEDIAN Median value of data set.
Q3 Third quartile: median of values to
right of median.
MAXΣ Maximum data value in data set.
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Statistics aplet 10-15
Two-variable
Plotting You can plot:
histograms ( )
box-and-whisker plots ( )
scatter plots ( ).
Once you have entered your data ( ), defined your
data set ( ), and defined your Fit model for two-
variable statistics (
SETUP-SYMB), you can plot your
data. You can plot up to five scatter or box-and-whisker
plots at a time. You can plot only one histogram at a time.
Statistic Definition
MEANX Mean of x- (independent) values.
ΣX Sum of x-values.
ΣX2 Sum of x
2
-values.
MEANY Mean of y- (dependent) values.
ΣY Sum of y-values.
ΣY2 Sum of y
2
-values.
ΣXY Sum of each xy.
SCOV Sample covariance of independent
and dependent data columns.
PCOV Population covariance of
independent and dependent data
columns
CORR Correlation coefficient of the
independent and dependent data
columns for a linear fit only
(regardless of the Fit chosen).
Returns a value from 0 to 1, where
1 is the best fit.
RELERR The relative error for the selected
fit. Provides a measure of accuracy
for the fit.
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10-16 Statistics aplet
To plot statistical
data
1. In Symbolic view ( ), select ( ) the data
sets you want to plot.
2. For one-variable data ( ), select the plot type in
Plot Setup (
SETUP-PLOT). Highlight STATPLOT,
press , select either Histogram or
BoxWhisker, and press .
3. For any plot, but especially for a histogram, adjust the
plotting scale and range in the Plot Setup view. If you
find histogram bars too fat or too thin, you can adjust
them by adjusting the HWIDTH setting.
4. Press . If you have not adjusted the Plot Setup
yourself, you can try select Auto Scale
.
Auto Scale can be relied upon to give a good starting
scale which can then be adjusted in the Plot Setup view.
Plot types
Histogram One-variable statistics.
The numbers below the plot
mean that the current bar
(where the cursor is) starts at
0 and ends at 2 (not
including 2), and the
frequency for this column, (that is, the number of data
elements that fall between 0 and 2) is 1. You can see
information about the next bar by pressing the key.
Box and
Whisker Plot
One-variable statistics.
The left whisker marks the
minimum data value. The
box marks the first quartile,
the median (where the cursor
is), and the third quartile.
The right whisker marks the maximum data value. The
numbers below the plot mean that this column has a
median of 13.
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Statistics aplet 10-17
Scatter Plot Two-variable statistics.
The numbers below the plot
indicate that the cursor is at
the first data point for S2, at
(1, 6). Press to move to
the next data point and
display information about it.
To connect the data points as
they are plotted, checkmark
CONNECT in the second
page of the Plot Setup. This is
not a regression curve.
Fitting a curve to 2VAR data
In the Plot view, press . This draws a curve to fit the
checked two-variable data set(s). See “To choose the fit”
on page 10-12.
The expression in Fit2
shows that the
slope=1.98082191781
and the y-
intercept= 2.2657.
Correlation
coefficient
The correlation coefficient is stored in the CORR variable.
It is a measure of fit to a linear curve only. Regardless of
the Fit model you have chosen, CORR relates to the linear
model.
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10-18 Statistics aplet
Relative Error The relative error is a measure of the error between
predicted values and actual values based on the specified
Fit. A smaller number means a better fit.
The relative error is stored in a variable named RELERR.
The relative error provides a measure of fit accuracy for
all fits, and it does depend on the Fit model you have
chosen.
HINT
In order to access the CORR and RELERR variables after
you plot a set of statistics, you must press to access
the numeric view and then to display the
correlation values. The values are stored in the variables
when you access the Symbolic view.
Setting up the plot (Plot setup view)
The Plot Setup view ( SETUP-PLOT) sets most of the
same plotting parameters as it does for the other built-in
aplets.
See “Setting up the plot (Plot view setup)” on page 2-5.
Settings unique to the Statistics aplet are as follows:
Plot type (1VAR) STATPLOT enables you to specify either a histogram or
a box-and-whisker plot for one-variable statistics (when
is set). Press to change the highlighted
setting
Histogram width HWIDTH enables you to specify the width of a histogram
bar. This determines how many bars will fit in the display,
as well as how the data is distributed (how many values
each bar represents).
Histogram range HRNG enables you to specify the range of values for a set
of histogram bars. The range runs from the left edge of the
leftmost bar to the right edge of the rightmost bar. You
can limit the range to exclude any values you suspect are
outliers.
Plotting mark
(2VAR)
S1MARK through S5MARK enables you to specify one of
five symbols to use to plot each data set. Press to
change the highlighted setting.
Connected points
(2VAR)
CONNECT (on the second page), when checkmarked,
connects the data points as they are plotted. The resulting
line is not the regression curve. The order of plotting is
according to the ascending order of independent values.
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Statistics aplet 10-19
For instance, the data set (1,1), (3,9), (4,16), (2,4) would
be plotted and traced in the order (1,1), (2,4), (3,9),
(4,16).
Trouble-shooting a plot
If you have problems plotting, check that you have the
following:
The correct or menu label on (Numeric
view).
The correct fit (regression model), if the data set is
two-variable.
Only the data sets to compute or plot are
checkmarked (Symbolic view).
The correct plotting range. Try using Auto
Scale (instead of ), or adjust the plotting
parameters (in Plot Setup) for the ranges of the axes
and the width of histogram bars (HWIDTH).
In mode, ensure that both paired columns contain
data, and that they are the same length.
In mode, ensure that a paired column of frequency
values is the same length as the data column that it refers
to.
Exploring the graph
The Plot view has menu keys for zooming, tracing, and
coordinate display. There are also scaling options under
. These options are described in“Exploring the
graph” on page 2-7.
Statistics aplet’s PLOT view keys
Key Meaning
CLEAR Erases the plot.
Offers additional pre-defined views
for splitting the screen, overlaying
plots, and autoscaling the axes.
Moves cursor to far left or far right.
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10-20 Statistics aplet
Calculating predicted values
The functions PREDX and PREDY estimate (predict) values
for X or Y given a hypothetical value for the other. The
estimation is made based on the curve that has been
calculated to fit the data according to the specified fit.
Find predicted
values
1. In Plot view, draw the regression curve for the data
set.
2. Press to move to the regression curve.
3. Press and enter the value of X. The cursor
jumps to the specified point on the curve and the
coordinate display shows X and the predicted value
of Y.
In HOME:
Enter PREDX(y-value) to find the predicted
value for the independent variable given a
hypothetical dependent value.
Displays ZOOM menu.
Turns trace mode on/off. The white
box appears next to the option when
Trace mode is active.
Turns fit mode on or off. Turning
on draws a curve to fit the data points
according to the current regression
model.
(2var
statistics only)
Enables you to specify a value on the
line of best fit to jump to or a data
point number to jump to.
Displays the equation of the
regression curve.
Hides and displays the menu key
labels. When the labels are hidden,
any menu key displays the (x,y)
coordinates. Pressing
redisplays the menu labels.
Key Meaning (Continued)
hp40g+.book Page 20 Friday, December 9, 2005 1:03 AM
Statistics aplet 10-21
Enter PREDY(x-value) to find the predicted value of the
dependent variable given a hypothetical independent
variable.
You can type PREDX and PREDY into the edit line, or you
can copy these function names from the MATH menu
under the Stat-Two category.
HINT
In cases where more than one fit curve is displayed, the
PREDY function uses the most recently calculated curve. In
order to avoid errors with this function, uncheck all fits
except the one that you want to work with, or use the Plot
View method.
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hp40g+.book Page 22 Friday, December 9, 2005 1:03 AM
Inference aplet 11-1
11
Inference aplet
About the Inference aplet
The Inference capabilities include calculation of
confidence intervals and hypothesis tests based on the
Normal Z-distribution or Student’s t-distribution.
Based on the statistics from one or two samples, you can
test hypotheses and find confidence intervals for the
following quantities:
mean
proportion
difference between two means
difference between two proportions
Example data When you first access an input form for an Inference test,
by default, the input form contains example data. This
example data is designed to return meaningful results that
relate to the test. It is useful for gaining an understanding
of what the test does, and for demonstrating the test. The
calculator’s on-line help provides a description of what
the example data represents.
Getting started with the Inference aplet
This example describes the Inference aplet’s options and
functionality by stepping you through an example using
the example data for the Z-Test on 1 mean.
Open the
Inference aplet
1. Open the Inference aplet.
Select Inference
.
The Inference aplet
opens in the Symbolic
view.
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11-2 Inference aplet
Inference aplet’s SYMB view keys
The table below summarizes the options available in
Symbolic view.
If you choose one of the hypothesis tests, you can choose
the alternative hypothesis to test against the null
hypothesis. For each test, there are three possible choices
for an alternative hypothesis based on a quantitative
comparison of two quantities. The null hypothesis is
always that the two quantities are equal.Thus, the
alternative hypotheses cover the various cases for the two
quantities being unequal: <, >, and .
In this section, we will use the example data for the Z-Test
on 1 mean to illustrate how the aplet works and what
features the various views present.
Hypothesis
Tests
Confidence Intervals
Z: 1 μ, the Z-Test
on 1 mean
Z-Int: 1 μ, the confidence
interval for 1 mean, based on
the Normal distribution
Z: μ
1
μ
2
, the
Z-Test on the
difference of two
means
Z-Int: μ
1
μ
2
, the confidence
interval for the difference of
two means, based on the
Normal distribution
Z: 1 π, the Z-Test
on 1 proportion
Z-Int: 1 π, the confidence
interval for 1 proportion,
based on the Normal
distribution
Z: π1 – π2, the
Z-Test on the
difference in two
proportions
Z-Int: π1 – π2, the confidence
interval for the difference of
two proportions, based on the
Normal distribution
T: 1 μ, the T-Test on
1 mean
T-Int: 1 μ, the confidence
interval for 1 mean, based on
the Student’s t-distribution
T: μ
1
μ
2
, the T-
Test on the
difference of two
means
T-Int: μ
1
μ
2
, the confidence
interval for the difference of
two means, based on the
Student’s t-distribution
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Inference aplet 11-3
Select the
inferential
method
2. Select the Hypothesis Test inferential method.
Select HYPOTH TEST
3. Define the type of test.
Z–Test: 1 μ
4. Select an alternative hypothesis.
μ< μ0
Enter data 5. Enter the sample statistics and population
parameters.
setup-NUM
The table below lists the fields in this view for our current
Z-Test: 1 μ example.
Field
name
Definition
μ0 Assumed population mean
σ Population standard deviation
Sample mean
n Sample size
α Alpha level for the test
x
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11-4 Inference aplet
By default, each field already contains a value.
These values constitute the example database and
are explained in the feature of this aplet.
Display on-line
help
6. To display the on-line
help, press
7. To close the on-line help,
press .
Display test
results in
numeric format
8. Display the test results in numeric format.
The test distribution value
and its associated
probability are
displayed, along with
the critical value(s) of the test and the associated
critical value(s) of the statistic.
Note: You can access the on-line help in Numeric
view.
Plot test results 9. Display a graphic view of the test results.
Horizontal axes are
presented for both the
distribution variable and
the test statistic. A
generic bell curve represents the probability
distribution function. Vertical lines mark the critical
value(s) of the test, as well as the value of the test
statistic. The rejection region is marked and the
test numeric results are displayed between the
horizontal axes.
Importing sample statistics from the Statistics aplet
The Inference aplet supports the calculation of confidence
intervals and the testing of hypotheses based on data in
the Statistics aplet. Computed statistics for a sample of
data in a column in any Statistics-based aplet can be
imported for use in the Inference aplet. The following
example illustrates the process.
R
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Inference aplet 11-5
A calculator produces the following 6 random numbers:
0.529, 0.295, 0.952, 0.259, 0.925, and 0.592
Open the
Statistics aplet
1. Open the Statistics aplet and reset the current
settings.
Select
Statistics
The Statistics aplet opens in the Numeric view.
Enter data 2. In the C1 column, enter the random numbers
produced by the calculator.
529
295
952
259
925
592
HINT
If the Decimal Mark setting in the Modes input form
( modes) is set to Comma, use instead of .
3. If necessary, select 1-variable statistics. Do this by
pressing the fifth menu key until is displayed
as its menu label.
Calculate
statistics
4. Calculate statistics.
The mean of 0.592
seems a little large
compared to the
expected value of 0.5. To see if the difference is
statistically significant, we will use the statistics
computed here to construct a confidence interval for
the true mean of the population of random numbers
and see whether or not this interval contains 0.5.
5. Press to close the computed statistics window.
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
11-6 Inference aplet
Open Inference
aplet
6. Open the Inference aplet and clear current settings.
Select
Inference
Select inference
method and
type
7. Select an inference method.
Select CONF INTERVAL
8. Select a distribution statistic type.
Select T-Int: 1 μ
Set up the
interval
calculation
9. Set up the interval calculation. Note: The default
values are derived from sample data from the on-line
help example.
Setup-NUM
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
Inference aplet 11-7
Import the data 10.Import the data from the Statistics aplet. Note: The
data from C1 is displayed by default.
Note: Press to see
the statistics before
importing them into the
Numeric Setup view.
Also, if there is more than one aplet based on the
Statistics aplet, you are prompted to choose one.
11.Specify a 90%
confidence interval in the C: field.
to move to
the C: field
0.9
Display Numeric
view
12.Display the confidence interval in the Numeric view.
Note: The interval setting is 0.5.
Display Plot
view
13.Display the confidence interval in the Plot view.
You can see, from the
second text row, that the
mean is contained within the 90% confidence
interval (CI) of 0.3469814 to 0.8370186.
Note: The graph is a simple, generic bell-curve. It is
not meant to accurately represent the t-distribution
with 5 degrees of freedom.
hp40g+.book Page 7 Friday, December 9, 2005 1:03 AM
11-8 Inference aplet
Hypothesis tests
You use hypothesis tests to test the validity of hypotheses
that relate to the statistical parameters of one or two
populations. The tests are based on statistics of samples
of the populations.
The HP 40gs hypothesis tests use the Normal
Z-distribution or Student’s t-distribution to calculate
probabilities.
One-Sample Z-Test
Menu name Z-Test: 1 μ
On the basis of statistics from a single sample, the
One-Sample Z-Test measures the strength of the evidence
for a selected hypothesis against the null hypothesis. The
null hypothesis is that the population mean equals a
specified value Η
0
: μ = μ
0
.
You select one of the following alternative hypotheses
against which to test the null hypothesis:
Inputs The inputs are:
H
1
:μ
1
μ
2
<
H
1
:μ
1
μ
2
>
H
1
:μ
1
μ
2
Field name Definition
Sample mean.
n Sample size.
μ
0
Hypothetical population mean.
σ Population standard deviation.
α Significance level.
x
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
Inference aplet 11-9
Results The results are:
Two-Sample Z-Test
Menu name Z-Test: μ1–μ2
On the basis of two samples, each from a separate
population, this test measures the strength of the evidence
for a selected hypothesis against the null hypothesis. The
null hypothesis is that the mean of the two populations are
equal (H
0
: μ1= μ2).
You select one of the following alternative hypotheses
against which to test the null hypothesis:
Inputs The inputs are:
Result Description
Test Z Z-test statistic.
Prob Probability associated with the
Z-Test statistic.
Critical Z Boundary values of Z
associated with the α level that
you supplied.
Critical
Boundary values of required
by the α value that you
supplied.
x
x
H
1
:μ
1
μ
2
<
H
1
:μ
1
μ
2
>
H
1
:μ
1
μ
2
Field name Definition
Sample 1 mean.
Sample 2 mean.
n1 Sample 1 size.
n2 Sample 2 size.
σ1 Population 1 standard
deviation.
x
1
x
2
hp40g+.book Page 9 Friday, December 9, 2005 1:03 AM
11-10 Inference aplet
Results The results are:
One-Proportion Z-Test
Menu name Z-Test:
On the basis of statistics from a single sample, this test
measures the strength of the evidence for a selected
hypothesis against the null hypothesis. The null hypothesis
is that the proportion of successes in the two populations
is equal: H
0
: π= π
0
You select one of the following alternative hypotheses
against which to test the null hypothesis:
σ2 Population 2 standard
deviation.
α Significance level.
Field name Definition
Result Description
Test Z Z-Test statistic.
Prob Probability associated with the
Z-Test statistic.
Critical Z Boundary value of Z
associated with the α level that
you supplied.
H
1
:ππ
0
<
H
1
:ππ
0
>
H
1
:ππ
0
hp40g+.book Page 10 Friday, December 9, 2005 1:03 AM
Inference aplet 11-11
Inputs The inputs are:
Results The results are:
Two-Proportion Z-Test
Menu name Z-Test: π1 – π2
On the basis of statistics from two samples, each from a
different population, the Two-Proportion Z-Test measures
the strength of the evidence for a selected hypothesis
against the null hypothesis. The null hypothesis is that the
proportion of successes in the two populations is equal
H0: π
1
= π
2
.
You select one of the following alternative hypotheses
against which to test the null hypothesis:
Field name Definition
x Number of successes in the sample.
n Sample size.
π
0
Population proportion of successes.
α Significance level.
Result Description
Test P Proportion of successes in the sample.
Test Z Z-Test statistic.
Prob Probability associated with the Z-Test
statistic.
Critical Z Boundary value of Z associated with
the level you supplied.
H
1
:π
1
π
2
<
H
1
:π
1
π
2
>
H
1
:π
1
π
2
hp40g+.book Page 11 Friday, December 9, 2005 1:03 AM
11-12 Inference aplet
Inputs The inputs are:
Results The results are:
One-Sample T-Test
Menu name T-Test: 1 μ
The One-sample T-Test is used when the population
standard deviation is not known. On the basis of statistics
from a single sample, this test measures the strength of the
evidence for a selected hypothesis against the null
hypothesis. The null hypothesis is that the sample mean
has some assumed value,
Η
0
:μ = μ
0
You select one of the following alternative hypotheses
against which to test the null hypothesis:
Field name Definition
X1 Sample 1 mean.
X2 Sample 2 mean.
n1 Sample 1 size.
n2 Sample 2 size.
α Significance level.
Result Description
Test π1–π2 Difference between the
proportions of successes in the
two samples.
Test Z Z-Test statistic.
Prob Probability associated with the
Z-Test statistic.
Critical Z Boundary values of Z
associated with the α level that
you supplied.
H
1
:μμ
0
<
H
1
:μμ
0
>
H
1
:μμ
0
hp40g+.book Page 12 Friday, December 9, 2005 1:03 AM
Inference aplet 11-13
Inputs The inputs are:
Results The results are:
Field name Definition
Sample mean.
Sx Sample standard deviation.
n Sample size.
μ0 Hypothetical population mean.
α Significance level.
x
Result Description
Test T T-Test statistic.
Prob Probability associated with the
T-Test statistic.
Critical T Boundary value of T associated
with the α level that you
supplied.
Critical
Boundary value of required
by the α value that you
supplied.
x
x
hp40g+.book Page 13 Friday, December 9, 2005 1:03 AM
11-14 Inference aplet
Two-Sample T-Test
Menu name T-Test: μ1 – μ2
The Two-sample T-Test is used when the population
standard deviation is not known. On the basis of statistics
from two samples, each sample from a different
population, this test measures the strength of the evidence
for a selected hypothesis against the null hypothesis. The
null hypothesis is that the two populations means are
equal H
0
: μ
1
= μ
2
.
You select one of the following alternative hypotheses
against which to test the null hypothesis
Inputs The inputs are:
H
1
:μ
1
μ
2
<
H
1
:μ
1
μ
2
>
H
1
:μ
1
μ
2
Field
name
Definition
Sample 1 mean.
Sample 2 mean.
S1 Sample 1 standard deviation.
S2 Sample 2 standard deviation.
n1 Sample 1 size.
n2 Sample 2 size.
α Significance level.
_Pooled? Check this option to pool samples
based on their standard deviations.
x1
x2
hp40g+.book Page 14 Friday, December 9, 2005 1:03 AM
Inference aplet 11-15
Results The results are:
Confidence intervals
The confidence interval calculations that the HP 40gs can
perform are based on the Normal Z-distribution or
Student’s t-distribution.
One-Sample Z-Interval
Menu name Z-INT: μ 1
This option uses the Normal Z-distribution to calculate a
confidence interval for m, the true mean of a population,
when the true population standard deviation, s, is known.
Inputs The inputs are:
Result Description
Test T T-Test statistic.
Prob Probability associated with the T-Test
statistic.
Critical T Boundary values of T associated with
the α level that you supplied.
Field
name
Definition
Sample mean.
σ Population standard deviation.
n Sample size.
C Confidence level.
x
hp40g+.book Page 15 Friday, December 9, 2005 1:03 AM
11-16 Inference aplet
Results The results are:
Two-Sample Z-Interval
Menu name Z-INT: μ1 μ2
This option uses the Normal Z-distribution to calculate a
confidence interval for the difference between the means
of two populations, μ
1
μ
2
, when the population standard
deviations, σ
1
and σ
2
, are known.
Inputs The inputs are:
Results The results are:
Result Description
Critical Z Critical value for Z.
μ min Lower bound for μ.
μ max Upper bound for μ.
Field
name
Definition
Sample 1 mean.
Sample 2 mean.
n1 Sample 1 size.
n2 Sample 2 size.
σ1 Population 1 standard deviation.
σ2 Population 2 standard deviation.
C Confidence level.
x1
x2
Result Description
Critical Z Critical value for Z.
μ Min
Lower bound for μ
1
μ
2
.
μ Max
Upper bound for μ
1
μ
2
.
Δ
Δ
hp40g+.book Page 16 Friday, December 9, 2005 1:03 AM
Inference aplet 11-17
One-Proportion Z-Interval
Menu name Z-INT: 1 π
This option uses the Normal Z-distribution to calculate a
confidence interval for the proportion of successes in a
population for the case in which a sample of size, n, has
a number of successes, x.
Inputs The inputs are:
Results The results are:
Two-Proportion Z-Interval
Menu name Z-INT: π1 – π2
This option uses the Normal Z-distribution to calculate a
confidence interval for the difference between the
proportions of successes in two populations.
Inputs The inputs are:
Field
name
Definition
x Sample success count.
n Sample size.
C Confidence level.
Result Description
Critical Z Critical value for Z.
π Min Lower bound for π.
π Max Upper bound for π.
Field
name
Definition
Sample 1 success count.
Sample 2 success count.
x
1
x2
hp40g+.book Page 17 Friday, December 9, 2005 1:03 AM
11-18 Inference aplet
Results The results are:
One-Sample T-Interval
Menu name T-INT: 1 μ
This option uses the Student’s t-distribution to calculate a
confidence interval for m, the true mean of a population,
for the case in which the true population standard
deviation, s, is unknown.
Inputs The inputs are:
n1 Sample 1 size.
n2 Sample 2 size.
C Confidence level.
Field
name
Definition (Continued)
Result Description
Critical Z Critical value for Z.
π Min
Lower bound for the difference between
the proportions of successes.
π Max
Upper bound for the difference between
the proportions of successes.
Δ
Δ
Field
name
Definition
Sample mean.
Sx Sample standard deviation.
n Sample size.
C Confidence level.
1
hp40g+.book Page 18 Friday, December 9, 2005 1:03 AM
Inference aplet 11-19
Results The results are:
Two-Sample T-Interval
Menu name T-INT: μ1 – μ2
This option uses the Student’s t-distribution to calculate a
confidence interval for the difference between the means
of two populations, μ1 – μ2, when the population
standard deviations, s1and s2, are unknown.
Inputs The inputs are:
Result Description
Critical T Critical value for T.
μ Min Lower bound for μ.
μ Max Upper bound for μ.
Field
name
Definition
Sample 1 mean.
Sample 2 mean.
s1 Sample 1 standard deviation.
s2 Sample 2 standard deviation.
n1 Sample 1 size.
n2 Sample 2 size.
C Confidence level.
_Pooled Whether or not to pool the samples
based on their standard deviations.
x1
x2
hp40g+.book Page 19 Friday, December 9, 2005 1:03 AM
11-20 Inference aplet
Results The results are:
Result Description
Critical T Critical value for T.
μ Min
Lower bound for μ
1
μ
2
.
μ Max
Upper bound for μ
1
μ
2
.
Δ
Δ
hp40g+.book Page 20 Friday, December 9, 2005 1:03 AM
Using the Finance Solver 12-1
12
Using the Finance Solver
The Finance Solver, or Finance aplet, is available by
using the APLET key in your calculator. Use the up and
down arrow keys to select the Finance aplet. Your screen
should look as follows:
Press the key or the soft menu key to
activate the aplet. The resulting screen shows the different
elements involved in the solution of financial problems
with your HP 40gs calculator.
Background information on and applications of financial
calculations are provided next.
Background
The Finance Solver application provides you with the
ability of solving time-value-of-money (TVM) and
amortization problems. These problems can be used for
calculations involving compound interest applications as
well as amortization tables.
Compound interest is the process by which earned
interest on a given principal amount is added to the
principal at specified compounding periods, and then the
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
12-2 Using the Finance Solver
combined amount earns interest at a certain rate.
Financial calculations involving compound interest
include savings accounts, mortgages, pension funds,
leases, and annuities.
Time Value of Money (TVM) calculations, as the name
implies, make use of the notion that a dollar today will be
worth more than a dollar sometime in the future. A dollar
today can be invested at a certain interest rate and
generate a return that the same dollar in the future cannot.
This TVM principle underlies the notion of interest rates,
compound interest and rates of return.
TVM transactions can be represented by using cash flow
diagrams. A cash flow diagram is a time line divided into
equal segments representing the compounding periods.
Arrows represent the cash flows, which could be positive
(upward arrows) or negative (downward arrows),
depending on the point of view of the lender or borrower.
The following cash flow diagram shows a loan from a
borrower's point of view:
On the other hand, the following cash flow diagram
shows a load from the lender's point of view:
In addition, cash flow diagrams specify when payments
occur relative to the compounding periods: at the
beginning of each period or at the end. The Finance
Solver application provides both of these payment
modes: Begin mode and End mode. The following cash
Present value (PV)
(Loan)
Money
received is
a positive
number
Money
paid out is
a negative
number
Equal periods
1
23
4
5
(PMT)
Future value
(FV)
Equal payments
Payment
(PMT)
Payment
(PMT)
Payment
(PMT)
Payment
(PMT)
}
}
}
}
}
FV
Equal payments
1
23
4
5
}
}
}
}
PMT
}
PMT PMT PMT PMT
Equal periods
PV
Loan
}
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Using the Finance Solver 12-3
flow diagram shows lease payments at the beginning of
each period.
The following cash flow diagram shows deposits into an
account at the end of each period.
As these cash-flow diagrams imply, there are five TVM
variables:
PV
1
23
4
5
FV
Capitalized
value of
lease
}
PMT PMT PMT PMTPMT
PV
1
23
4
5
FV
PMT PMT PMT PMT PMT
N The total number of compounding periods
or payments.
I%YR The nominal annual interest rate (or
investment rate). This rate is divided by
the number of payments per year (P/YR)
to compute the nominal interest rate per
compounding period -- which is the
interest rate actually used in TVM
calculations.
PV
The present value of the initial cash flow.
To a lender or borrower, PV is the amount
of the loan; to an investor, PV is the initial
investment. PV always occurs at the
beginning of the first period.
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
12-4 Using the Finance Solver
Performing TVM calculations
1. Launch the Financial Solver as indicated at the
beginning of this section.
2. Use the arrow keys to highlight the different fields and
enter the known variables in the TVM calculations,
pressing the soft-menu key after entering each
known value. Be sure that values are entered for at
least four of the five TVM variables (namely, N, I%YR,
PV, PMT, and FV).
3. If necessary, enter a different value for P/YR (default
value is 12, i.e., monthly payments).
4. Press the key to change the Payment mode (Beg
or End) as required.
5. Use the arrow keys to highlight the TVM variable you
wish to solve for and press the soft-menu key.
PMT
The periodic payment amount. The
payments are the same amount each
period and the TVM calculation assumes
that no payments are skipped. Payments
can occur at the beginning or the end of
each compounding period -- an option
you control by setting the Payment mode
to Beg or End.
FV
The future value of the transaction: the
amount of the final cash flow or the
compounded value of the series of
previous cash flows. For a loan, this is the
size of the final balloon payment (beyond
any regular payment due). For an
investment this is the cash value of an
investment at the end of the investment
period.
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Using the Finance Solver 12-5
Example 1 - Loan calculations
Suppose you finance the purchase of a car with a 5-year
loan at 5.5% annual interest, compounded monthly. The
purchase price of the car is $19,500, and the down
payment is $3,000. What are the required monthly
payments? What is the largest loan you can afford if your
maximum monthly payment is $300? Assume that the
payments start at the end of the first period.
Solution. The following cash flow diagram illustrates the
loan calculations:
Start the Finance Solver, selecting P/YR = 12 and End
payment option.
Enter the known TVM variables as shown in the
diagram above. Your input form should look as
follows:
Highlighting the PMT field, press the soft
menu key to obtain a payment of -315.17 (i.e., PMT
= -$315.17).
To determine the maximum loan possible if the
monthly payments are only $300, type the value
–300 in the PMT field, highlight the PV field, and
press the soft menu key. The resulting value is
PV = $15,705.85.
PV = $16,500
1
2
59
60
FV = 0
l%YR = 5.5
N = 5 x 12 = 60
P/YR = 12; End mode
PMT = ?
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
12-6 Using the Finance Solver
Example 2 - Mortgage with balloon payment
Suppose you have taken out a 30-year, $150,000 house
mortgage at 6.5% annual interest. You expect to sell the
house in 10 years, repaying the loan in a balloon
payment. Find the size of the balloon payment, the value
of the mortgage after 10 years of payment.
Solution. The following cash flow diagram illustrates the
case of the mortgage with balloon payment:
Start the Finance Solver, selecting P/YR = 12 and
End payment option.
Enter the known TVM variables as shown in the
diagram above. Your input form, for calculating
monthly payments for the 30-yr mortgage, should
look as follows:
Highlighting the PMT field, press the soft
menu key to obtain a payment of -948.10 (i.e., PMT
= -$948.10)
To determine the balloon payment or future value (FV)
for the mortgage after 10 years, use N = 120,
highlight the FV field, and press the soft menu
key. The resulting value is FV = -$127,164.19. The
negative value indicates a payment from the
homeowner. Check that the required balloon
payments at the end of 20 years (N=240) and 25
years (N = 300) are -$83,497.92 and
-$48,456.24, respectively.
PV = $150,000
1
2
59
60
l%YR = 6.5
N = 30 x 12 = 360 (for PMT)
N = 10 x 12 = 120 (for balloon payment)
P/YR = 12; End mode
PMT = ?
Balloon payment,
FV = ?
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
Using the Finance Solver 12-7
Calculating Amortizations
Amortization calculations, which also use the TVM
variables, determine the amounts applied towards
principal and interest in a payment or series of payments.
To calculate amortizations:
1. Start the Finance Solver as indicated at the beginning
of this section.
2. Set the following TVM variables:
a Number of payments per year (P/YR)
b Payment at beginning or end of periods
3. Store values for the TVM variables I%YR, PV, PMT,
and FV, which define the payment schedule.
4. Press the
soft menu key and enter the
number of payments to amortize in this batch.
5. Press the soft menu key to amortize a batch of
payments. The calculator will provide for you the
amount applied to interest, to principal, and the
remaining balance after this set of payments have
been amortized.
Example 3 - Amortization for home mortgage
For the data of Example 2 above, find the amortization of
the loan after the first 10 years (12x10 = 120 payments).
Pressing the soft menu key produces the
screen to the left. Enter 120 in the PAYMENTS field, and
press the soft menu key to produce the results
shown to the right.
To continue amortizing the loan:
1. Press the soft menu key to store the new
balance after the previous amortization as PV.
2. Enter the number of payments to amortize in the new
batch.
hp40g+.book Page 7 Friday, December 9, 2005 1:03 AM
12-8 Using the Finance Solver
3. Press the soft menu key to amortize the new
batch of payments. Repeat steps 1 through 3 as
often as needed.
Example 4 - Amortization for home mortgage
For the results of Example 3, show the amortization of the
next 10 years of the mortgage loan. First, press the
soft menu key. Then, keeping 120 in the PAYMENTS
field, press the soft menu key to produce the results
shown below.
To amortize a series of future payments starting at payment
p:
1. Calculate the balance of the loan at payment p-1.
2. Store the new balance in PV using the soft
menu key.
3. Amortize the series of payments starting at the new
PV.
The amortization operation reads the values from the
TVM variables, rounds the numbers it gets from PV and
PMT to the current display mode, then calculates the
amortization rounded to the same setting. The original
variables are not changed, except for PV, which is
updated after each amortization.
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
Using mathematical functions 13-1
13
Using mathematical functions
Math functions
The HP 40gs contains many math functions. The functions
are grouped in categories. For example, the Matrix
category contains functions for manipulating matrices.
The Probability category (shown as Prob. on the MATH
menu) contains functions for working with probability.
To use a math function in HOME view, you enter the
function onto the command line, and include the
arguments in parentheses after the function. You can also
select a math function from the MATH menu.
Note that this chapter covers only the use of mathematical
functions in HOME view. The use of mathematical
functions in CAS is described in Chapter14, “Computer
Algebra System (CAS)”.
The MATH menu
The MATH menu provides access to math functions,
physical constants, and programming constants. You can
also access CAS commands.
The MATH menu is organized by category. For each
category of functions on the left, there is a list of function
names on the right. The highlighted category is the
current category.
When you press , you see the menu list of
Math categories in the left column and the
corresponding functions of the highlighted category
in the right column. The menu key indicates
that the MATH FUNCTIONS menu list is active.
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
13-2 Using mathematical functions
To select a function 1. Press to display the MATH menu. The
categories appear in alphabetical order.
2. Press or to scroll through the categories. To
jump directly to a category, press the first letter of the
category’s name. Note: You do not need to press
first.
3. The list of functions (on the right) applies to the
currently highlighted category (on the left). Use
and to switch between the category list and the
function list.
4. Highlight the name of the function you want and
press . This copies the function name (and an
initial parenthesis, if appropriate) to the edit line.
NOTE
If you press while the MATH menu is open, CAS
functions and commands are displayed. You can select a
CAS function or command in the same way that you
select a function from the MATH menu (by pressing the
arrow keys and then ). The function or command
selected appears on the edit line in HOME (and with an
initial parenthesis, if appropriate).
Function categories (MATH menu)
Math functions by category
Syntax Each function’s definition includes its syntax, that is, the
exact order and spelling of a function’s name, its
delimiters (punctuation), and its arguments. Note that the
syntax for a function does not require spaces.
Calculus
Complex
numbers
Constant
Convert
Hyperbolic
trigonometry
(Hyperb.)
Lists
Loop
Matrix
Polynomial
Probability
Real numbers
(Real)
Two-variable
statistics
(Stat-Two)
Symbolic
Tests
Trigonometry
(Trig)
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Using mathematical functions 13-3
Functions common to keyboard and menus
These functions are common to the keyboard and MATH
menu.
Keyboard functions
The most frequently used functions are available directly
from the keyboard. Many of the keyboard functions also
accept complex numbers as arguments.
π
For a description, see “p” on
page 13-8.
ARG
For a description, see “ARG” on
page 13-7.
For a description, see “ on
page 11-7.
AND
For a description, see “AND” on
page 13-19.
!
For a description, see
“COMB(5,2) returns 10. That is,
there are ten different ways that
five things can be combined two
at a time.!” on page 13-12.
For a description, see “S” on
page 13-11.
EEX
For a description, see “Scientific
notation (powers of 10)” on
page 1-20.
For a description, see “ ” on
page 11-7.
The multiplicative inverse
function finds the inverse of a
square matrix, and the
multiplicative inverse of a real or
complex number. Also works on
a list containing only these object
types.
x
1
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
13-4 Using mathematical functions
,,, Add, Subtract, Multiply, Divide. Also accepts complex
numbers, lists and matrices.
value1+ value2, etc.
e
x
Natural exponential. Also accepts complex numbers.
e^value
Example
e^5 returns 148.413159103
Natural logarithm. Also accepts complex numbers.
LN(value)
Example
LN(1) returns 0
10
x
Exponential (antilogarithm). Also accepts complex
numbers.
10^value
Example
10^3 returns 1000
Common logarithm. Also accepts complex numbers.
LOG(value)
Example
LOG(100) returns 2
,, Sine, cosine, tangent. Inputs and outputs depend on the
current angle format (Degrees, Radians, or Grads).
SIN(value)
COS(value)
TAN(value)
Example
TAN(45) returns 1 (Degrees mode).
ASIN Arc sine: sin
–1
x. Output range is from –90° to 90°, π/2
to π/2, or –100 to 100 grads. Inputs and outputs depend
on the current angle format. Also accepts complex
numbers.
ASIN(value)
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Using mathematical functions 13-5
Example
ASIN(1) returns 90 (Degrees mode).
ACOS Arc cosine: cos
–1
x. Output range is from 0° to 180°, 0 to
π, or 0 to 200 grads. Inputs and outputs depend on the
current angle format. Also accepts complex numbers.
Output will be complex for values outside the normal
COS domain of .
ACOS(value)
Example
ACOS(1) returns 0 (Degrees mode).
ATAN Arc tangent: tan
–1
x. Output range is from –90° to 90°,
2π/2 to π/2, or –100 to 100 grads. Inputs and outputs
depend on the current angle format. Also accepts
complex numbers.
ATAN(value)
Example
ATAN(1) returns 45 (Degrees mode).
Square. Also accepts complex numbers.
value
2
Example
18
2
returns 324
Square root. Also accepts complex numbers.
value
Example
returns 18
Negation. Also accepts complex numbers.
value
Example
-(1,2) returns (-1,-2)
Power (x raised to y). Also accepts complex numbers.
value^power
1 x 1≤≤
324
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
13-6 Using mathematical functions
Example
2^8 returns 256
ABS Absolute value. For a complex number, this is .
ABS(value)
ABS((x,y))
Example
ABS(–1) returns 1
ABS((1,2)) returns 2.2360679775
Takes the nth root of x.
root NTHROOT value
Example
3 NTHROOT 8 returns 2
Calculus functions
The symbols for differentiation and integration are
available directly form the keyboard— and S
respectively—as well as from the MATH menu.
Differentiates expression with respect to the variable of
differentiation. From the command line, use a formal
name (S1, etc.) for a non-numeric result. See “Finding
derivatives” on page 13-21.
variable(expression)
Example
s1(s1
2
+3*s1) returns 2*s1+3
Integrates expression from lower to upper limits with
respect to the variable of integration. To find the definite
integral, both limits must have numeric values (that is, be
numbers or real variables). To find the indefinite integral,
one of the limits must be a formal variable (s1, etc).
(lower, upper, expression, variable)
See “Using formal variables” on page 13-20 for
further details.
x
2
y
2
+
n
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
Using mathematical functions 13-7
Example
(0,s1,2*X+3,X)
finds the indefinite result 3*s1+2*(s1^2/2)
See “To find the indefinite integral using formal
variables” on page 13-23 for more information on
finding indefinite integrals.
TAYLOR Calculates the nth order Taylor polynomial of expression
at the point where the given variable = 0.
TAYLOR (expression, variable, n)
Example
TAYLOR(1 + sin(s1)
2
,s1,5)with Radians
angle measure and Fraction number format (set in
MODES) returns 1+s1^2+-(1/3)*s1^4.
Complex number functions
These functions are for complex numbers only. You can
also use complex numbers with all trigonometric and
hyperbolic functions, and with some real-number and
keyboard functions. Enter complex numbers in the form
(x,y), where x is the real part and y is the imaginary part.
ARG Argument. Finds the angle defined by a complex number.
Inputs and outputs use the current angle format set in
Modes.
ARG((x, y))
Example
ARG((3,3)) returns 45 (Degrees mode)
CONJ Complex conjugate. Conjugation is the negation (sign
reversal) of the imaginary part of a complex number.
CONJ((x, y))
Example
CONJ((3,4)) returns (3,-4)
IM Imaginary part, y, of a complex number, (x, y).
IM ((x, y))
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13-8 Using mathematical functions
Example
IM((3,4)) returns 4
RE Real part x, of a complex number, (x, y).
RE((x, y))
Example
RE((3,4)) returns 3
Constants
The constants available from the MATH FUNCTIONS
menu are mathematical constants. These are described in
this section. The HP 40gs has two other menus of
constants: program constants and physical constants.
These are described in “Program constants and physical
constants” on page 13-24.
e Natural logarithm base. Internally represented as
2.71828182846.
e
i Imaginary value for , the complex number (0,1).
i
MAXREAL Maximum real number. Internally represented as
9.99999999999 x 10
499
.
MAXREAL
MINREAL Minimum real number. Internally represented as
1x10
-499
.
MINREAL
π Internally represented as 3.14159265359.
π
Conversions
The conversion functions are found on the Convert
menu. They enable you to make the following
conversions.
1
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
Using mathematical functions 13-9
C Convert from Fahrenheit to Celcius.
Example
C(212) returns 100
F Convert from Celcius to Fahrenheit.
Example
F(0) returns 32
CM Convert from inches to centimeters.
IN Convert from centimeters to inches.
L Convert from US gallons to liters.
LGAL Convert from liters to US gallons.
KG Convert from pounds to kilograms.
LBS Convert from kilograms to pounds.
KM Convert from miles to kilometers.
MILE Convert from kilometers to miles.
DEG Convert from radians to degrees.
RAD Convert from degrees to radians.
Hyperbolic trigonometry
The hyperbolic trigonometry functions can also take
complex numbers as arguments.
ACOSH Inverse hyperbolic cosine : cosh
–1
x.
ACOSH(value)
ASINH Inverse hyperbolic sine : sinh
–1
x.
ASINH(value)
ATANH Inverse hyperbolic tangent : tanh
–1
x.
ATANH(value)
hp40g+.book Page 9 Friday, December 9, 2005 1:03 AM
13-10 Using mathematical functions
COSH Hyperbolic cosine
COSH(value)
SINH Hyperbolic sine.
SINH(value)
TANH Hyperbolic tangent.
TANH(value)
ALOG Antilogarithm (exponential). This is more accurate than
10^x due to limitations of the power function.
ALOG(value)
EXP Natural exponential. This is more accurate than due
to limitations of the power function.
EXP(value)
EXPM1 Exponent minus 1 : . This is more accurate than
EXP when x is close to zero.
EXPM1(value)
LNP1 Natural log plus 1 : ln(x+1). This is more accurate than
the natural logarithm function when x is close to zero.
LNP1(value)
List functions
These functions work on list data. See “List functions” on
page 19-6.
Loop functions
The loop functions display a result after evaluating an
expression a given number of times.
ITERATE Repeatedly for #times evaluates an expression in terms of
variable. The value for variable is updated each time,
starting with initialvalue.
ITERATE(expression, variable, initialvalue,
#times)
Example
ITERATE(X
2
,X,2,3) returns 256
e
x
e
x
1
hp40g+.book Page 10 Friday, December 9, 2005 1:03 AM
Using mathematical functions 13-11
RECURSE Provides a method of defining a sequence without using
the Symbolic view of the Sequence aplet. If used with |
(“where”), RECURSE will step through the evaluation.
RECURSE(sequencename, term
n
, term
1
, term
2
)
Example
RECURSE(U,U(N-1)*N,1,2) U1(N)
Stores a factorial-calculating function named U1.
When you enter U1(5), for example, the function
calculates 5! (120).
Σ Summation. Finds the sum of expression with respect to
variable from initialvalue to finalvalue.
Σ(variable=initialvalue, finalvalue, expression)
Example
Σ(C=1,5,C
2
) returns 55.
Matrix functions
These functions are for matrix data stored in matrix
variables. See “Matrix functions and commands” on
page 18-10.
Polynomial functions
Polynomials are products of constants (coefficients) and
variables raised to powers (terms).
POLYCOEF Polynomial coefficients. Returns the coefficients of the
polynomial with the specified roots.
POLYCOEF ([roots])
Example
To find the polynomial with roots 2, –3, 4, –5:
POLYCOEF([2,-3,4,-5]) returns[1,2,-25,
-26,120], representing x
4
+2x
3
–25x
2
–26x+120.
POLYEVAL Polynomial evaluation. Evaluates a polynomial with the
specified coefficients for the value of x.
POLYEVAL([coefficients], value)
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13-12 Using mathematical functions
Example
For x
4
+2x
3
–25x
2
–26x+120:
POLYEVAL([1,2,-25,-26,120],8) returns
3432.
POLYFORM Polynomial form. Creates a polynomial in variable1 from
expression.
POLYFORM(expression, variable1)
Example
POLYFORM((X+1)^2+1,X) returns X^2+2*X+2.
POLYROOT Polynomial roots. Returns the roots for the nth-order
polynomial with the specified n+1 coefficients.
POLYROOT([coefficients])
Example
For x
4
+2x
3
–25x
2
–26x+120:
POLYROOT([1,2,-25,-26,120]) returns
[2,-3,4,-5].
HINT
The results of POLYROOT will often not be easily seen in
HOME due to the number of decimal places, especially if
they are complex numbers. It is better to store the results
of POLYROOT to a matrix.
For example, POLYROOT([1,0,0,-8] M1 will
store the three complex cube roots of 8 to matrix M1 as
a complex vector. Then you can see them easily by going
to the Matrix Catalog. and access them individually in
calculations by referring to M1(1), M1(2) etc.
Probability functions
COMB Number of combinations (without regard to order) of n
things taken r at a time: n!/(r!(n-r)).
COMB(n, r)
Example
COMB(5,2) returns 10. That is, there are ten
different ways that five things can be combined two
at a time.!
hp40g+.book Page 12 Friday, December 9, 2005 1:03 AM
Using mathematical functions 13-13
Factorial of a positive integer. For non-integers, ! = Γ(x +
1). This calculates the gamma function.
value!
PERM Number of permutations (with regard to order) of n things
taken r at a time: n!/(r!(n-r)!
PERM (n, r)
Example
PERM(5,2) returns 20. That is, there are 20
different permutations of five things taken two at a
time.
RANDOM Random number (between zero and 1). Produced by a
pseudo-random number sequence. The algorithm used in
the RANDOM function uses a seed number to begin its
sequence. To ensure that two calculators must produce
different results for the RANDOM function, use the
RANDSEED function to seed different starting values
before using RANDOM to produce the numbers.
RANDOM
HINT
The setting of Time will be different for each calculator, so
using RANDSEED(Time) is guaranteed to produce a set of
numbers which are as close to random as possible. You
can set the seed using the command RANDSEED.
UTPC Upper-Tail Chi-Squared Probability given degrees of
freedom, evaluated at value. Returns the probability that
a χ
2
random variable is greater than value.
UTPC(degrees, value)
UTPF Upper-Tail Snedecor’s F Probability given numerator
degrees of freedom and denominator degrees of freedom
(of the F distribution), evaluated at value. Returns the
probability that a Snedecor's F random variable is
greater than value.
UTPF(numerator, denominator, value)
UTPN Upper-Tail Normal Probability given mean and variance,
evaluated at value. Returns the probability that a normal
random variable is greater than value for a normal
distribution. Note: The variance is the square of the
standard deviation.
UTPN(mean, variance, value)
hp40g+.book Page 13 Friday, December 9, 2005 1:03 AM
13-14 Using mathematical functions
UTPT Upper-Tail Student’s t-Probability given degrees of
freedom, evaluated at value. Returns the probability that
the Student's t- random variable is greater than value.
UTPT(degrees, value)
Real-number functions
Some real-number functions can also take complex
arguments.
CEILING Smallest integer greater than or equal to value.
CEILING(value)
Examples
CEILING(3.2) returns 4
CEILING(-3.2) returns -3
DEGRAD Degrees to radians. Converts value from Degrees angle
format to Radians angle format.
DEGRAD(value)
Example
DEGRAD(180) returns 3.14159265359, the
value of π.
FLOOR Greatest integer less than or equal to value.
FLOOR(value)
Example
FLOOR(-3.2) returns -4
FNROOT Function root-finder (like the Solve aplet). Finds the value
for the given variable at which expression most nearly
evaluates to zero. Uses guess as initial estimate.
FNROOT(expression, variable, guess)
Example
FNROOT(M*9.8/600-1,M,1) returns
61.2244897959.
FRAC Fractional part.
FRAC(value)
Example
FRAC (23.2) returns .2
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Using mathematical functions 13-15
HMS Hours-minutes-seconds to decimal. Converts a number or
expression in H.MMSSs format (time or angle that can
include fractions of a second) to x.x format (number of
hours or degrees with a decimal fraction).
HMS(H.MMSSs)
Example
HMS(8.30) returns 8.5
HMS Decimal to hours-minutes-seconds. Converts a number or
expression in x.x format (number of hours or degrees
with a decimal fraction) to H.MMSSs format (time or
angle up to fractions of a second).
HMS(x.x)
Example
HMS(8.5) returns 8.3
INT Integer part.
INT(value)
Example
INT(23.2) returns 23
MANT Mantissa (significant digits) of value.
MANT(value)
Example
MANT(21.2E34) returns 2.12
MAX Maximum. The greater of two values.
MAX(value1, value2)
Example
MAX(210,25) returns 210
MIN Minimum. The lesser of two values.
MIN(value1, value2)
Example
MIN(210,25) returns 25
MOD Modulo. The remainder of value1/value2.
value1 MOD value2
hp40g+.book Page 15 Friday, December 9, 2005 1:03 AM
13-16 Using mathematical functions
Example
9 MOD 4 returns 1
% x percent of y; that is, x/100*y.
%(x, y)
Example
%(20,50) returns 10
%CHANGE Percent change from x to y, that is, 100(y–x)/x.
%CHANGE(x, y)
Example
%CHANGE(20,50) returns 150
%TOTAL Percent total : (100)y/x. What percentage of x, is y.
%TOTAL(x, y)
Example
%TOTAL(20,50) returns 250
RADDEG Radians to degrees. Converts value from radians to
degrees.
RADDEG (value)
Example
RADDEG(π) returns 180
ROUND Rounds value to decimal places. Accepts complex
numbers.
ROUND(value, places)
Round can also round to a number of significant digits as
showed in example 2.
Examples
ROUND(7.8676,2) returns 7.87
ROUND (0.0036757,-3) returns 0.00368
SIGN Sign of value. If positive, the result is 1. If negative, –1. If
zero, result is zero. For a complex number, this is the unit
vector in the direction of the number.
SIGN(value)
SIGN((x, y))
hp40g+.book Page 16 Friday, December 9, 2005 1:03 AM
Using mathematical functions 13-17
Examples
SIGN (–2) returns –1
SIGN((3,4)) returns (.6,.8)
TRUNCATE Truncates value to decimal places. Accepts complex
numbers.
TRUNCATE(value, places)
Example
TRUNCATE(2.3678,2) returns 2.36
XPON Exponent of value.
XPON(value)
Example
XPON(123.4) returns 2
Two-variable statistics
These are functions for use with two-variable statistics.
See “Two-variable” on page 10-15.
Symbolic functions
The symbolic functions are used for symbolic
manipulations of expressions. The variables can be
formal or numeric, but the result is usually in symbolic
form (not a number). You will find the symbols for the
symbolic functions = and | (where) in the CHARS menu
(
CHARS) as well as the MATH menu.
= (
equals
) Sets an equality for an equation. This is not a logical
operator and does not store values. (See “Test functions”
on page 13-19.)
expression1=expression2
ISOLATE Isolates the first occurrence of variable in expression=0
and returns a new expression, where
variable=newexpression. The result is a general solution
that represents multiple solutions by including the (formal)
variables S1 to represent any sign and n1 to represent
any integer.
ISOLATE(expression, variable)
hp40g+.book Page 17 Friday, December 9, 2005 1:03 AM
13-18 Using mathematical functions
Examples
ISOLATE(2*X+8,X) returns -4
ISOLATE(A+B*X/C,X) returns -(A*C/B)
LINEAR? Tests whether expression is linear for the specified
variable. Returns 0 (false) or 1 (true).
LINEAR?(expression, variable)
Example
LINEAR?((X^2-1)/(X+1),X) returns 0
QUAD Solves quadratic expression=0 for variable and returns
a new expression, where variable=newexpression. The
result is a general solution that represents both positive
and negative solutions by including the formal variable
S1 to represent any sign: + or – .
QUAD(expression, variable)
Example
QUAD((X-1)
2
-7,X) returns (2+s1*(2*7))/2
QUOTE Encloses an expression that should not be evaluated
numerically.
QUOTE(expression)
Examples
QUOTE(SIN(45)) F1(X) stores the
expression SIN(45) rather than the value of SIN(45).
Another method is to enclose the expression in single
quotes.
For example, X^3+2*X F1(X) puts the
expression X^3+2*X into F1(X) in the Function
aplet.
| (
where
) Evaluates expression where each given variable is set to
the given value. Defines numeric evaluation of a symbolic
expression.
expression|(variable1=value1, variable2=value2,...)
Example
3*(X+1)|(X=3) returns 12.
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Using mathematical functions 13-19
Test functions
The test functions are logical operators that always return
either a 1 (true) or a 0 (false).
< Less than. Returns 1 if true, 0 if false.
value1<value2
Less than or equal to. Returns 1 if true, 0 if false.
value1value2
= = Equals (logical test). Returns 1 if true, 0 if false.
value1==value2
Not equal to. Returns 1 if true, 0 if false.
value1value2
> Greater than. Returns 1 if true, 0 if false.
value1>value2
Greater than or equal to. Returns 1 if true, 0 if false.
value1value2
AND Compares value1 and value2. Returns 1 if they are both
non-zero, otherwise returns 0.
value1 AND value2
IFTE If expression is true, do the trueclause; if not, do the
falseclause.
IFTE(expression, trueclause, falseclause)
Example
IFTE(X>0,X
2
,X
3
)
NOT Returns 1 if value is zero, otherwise returns 0.
NOT value
OR Returns 1 if either value1 or value2 is non-zero, otherwise
returns 0.
value1 OR value2
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13-20 Using mathematical functions
XOR Exclusive OR. Returns 1 if either value1 or value2—but
not both of them—is non-zero, otherwise returns 0.
value1 XOR value2
Trigonometry functions
The trigonometry functions can also take complex
numbers as arguments. For SIN, COS, TAN, ASIN,
ACOS, and ATAN, see the Keyboard category.
ACOT Arc cotangent.
ACOT(value)
ACSC Arc cosecant.
ACSC(value)
ASEC Arc secant.
ASEC(value)
COT Cotangent: cosx/sinx.
COT(value)
CSC Cosecant: 1/sinx
CSC(value)
SEC Secant: 1/cosx.
SEC(value)
Symbolic calculations
Although CAS provides the richest environment for
performing symbolic calculations, you can perform some
symbolic calculations in HOME and with the Function
aplet. CAS functions that you can perform in HOME (such
as DERVX and INTVX) are discussed in “Using CAS
functions in HOME” on page 14-7.
In HOME When you perform calculations that contain normal
variables, the calculator substitutes values for any
variables. For example, if you enter A+B on the command
line and press , the calculator retrieves the values
for A and B from memory and substitutes them in the
calculation.
Using formal
variables
To perform symbolic calculations, for example symbolic
differentiations and integrations, you need to use formal
hp40g+.book Page 20 Friday, December 9, 2005 1:03 AM
Using mathematical functions 13-21
names. The HP 40gs has six formal names available for
use in symbolic calculations. These are S1 to S5. When
you perform a calculation that contains a formal name,
the HP 40gs does not carry out any substitutions.
You can mix formal names and real variables. Evaluating
(A+B+S1)
2
will evaluate A+B, but not S1.
If you need to evaluate an expression that contains formal
names numerically, you use the | (where) command,
listed in the Math menu under the Symbolic category.
For example to evaluate (S1*S2)
2
when
S1=2 and
S2=4, you would enter the calculation as follows:
(The | symbol is in the CHARS menu: press
CHARS.
The = sign is listed in the MATH menu under Symbolic
functions.)
Symbolic
calculations in
the Function
aplet
You can perform symbolic operations in the Function
aplet’s Symbolic view. For example, to find the derivative
of a function in the Function aplet’s Symbolic view, you
define two functions and define the second function as a
derivative of the first function. You then evaluate the
second function. See “To find derivatives in the Function
aplet’s Symbolic view” on page 13-22 for an example.
Finding derivatives
The HP 40gs can perform symbolic differentiation on
some functions. There are two ways of using the HP 40gs
to find derivatives.
You can perform differentiations in HOME by using
the formal variables, S1 to S5.
You can perform differentiations of functions of X in
the Function aplet.
To find derivatives
in HOME
To find the derivative of the function in HOME, use a
formal variable in place of X. If you use X, the
hp40g+.book Page 21 Friday, December 9, 2005 1:03 AM
13-22 Using mathematical functions
differentiation function substitutes the value that X holds,
and returns a numeric result.
For example, consider the function:
1. Enter the differentiation function onto the command
line, substituting S1 in place of X.
S1
S1
2
S1
2. Evaluate the function.
3. Show the result.
To find derivatives
in the Function
aplet’s Symbolic
view
To find the derivative of the function in the Function aplet’s
Symbolic view, you define two functions and define the
second function as a derivative of the first function. For
example, to differentiate :
1. Access the Function aplet’s Symbolic view and define
F1.
2
2. Define F2(X) as the
derivative of F(1).
dx x(
2
)sin( 2 x())cos+
x
2
()sin 2 xcos+
hp40g+.book Page 22 Friday, December 9, 2005 1:03 AM
Using mathematical functions 13-23
F1
3. Select F2(X) and
evaluate it.
4. Press to display
the result. Note: Use
the arrow keys to view
the entire function.
|
You could also just define
.
To find the
indefinite integral
using formal
variables
For example, to find the indefinite integral of
use:
1. Enter the function.
0
S1 3
X 5
X
2. Show the result format.
3. Press to close the
show window.
F1 x() xx
2
()2 x()cos+sin()d=
3x
2
5 xd
(
)
XXS ,53,1,0
2
hp40g+.book Page 23 Friday, December 9, 2005 1:03 AM
13-24 Using mathematical functions
4. Copy the result and
evaluate.
Thus, substituting X for S1, it can be seen that:
This result is derived from substituting X=S1 and X=0 into
the original expression found in step 1. However,
substituting X=0 will not always evaluate to zero and may
result in an unwanted constant.
To see this, consider:
The ‘extra’ constant of
32/5 results from the
substitution of into
(x –2)
5
/5, and should be
disregarded if an
indefinite integral is
required.
Program constants and physical constants
When you press , three menus of functions and
constants become available:
the math functions menu (which appears by default)
the program constants menu, and
the physical constants menu.
The math functions menu is described extensively earlier
in this chapter.
3x
2
5 x 5x–3
x
3
3
-----
X
X()
---------------
⎝⎠
⎜⎟
⎜⎟
⎜⎟
⎛⎞
+=d
x 2()
4
x
x( 2 )
5
5
-------------------
=d
x 0=
hp40g+.book Page 24 Friday, December 9, 2005 1:03 AM
Using mathematical functions 13-25
Program constants
The program constants are numbers that have been
assigned to various calculator settings to enable you to
test for or specify such a setting in a program. For
example, the various display formats are assigned the
following numbers:
1 Standard
2 Fixed
3 Scientific
4 Engineering
5 Fraction
6 Mixed fraction
In a program, you could store the constant number of a
particular format into a variable and then subsequently
test for that particular format.
To access the menu of program constants:
1. Press .
2. Press .
3. Use the arrow keys to navigate through the options.
4. Click and then to display the number
assigned to the option you selected in the previous
step.
The use of program constants is illustrated in more detail
in “Programming” on page 21-1
Physical constants
There are 29 physical constants—from the fields of
chemistry, physics and quantum mechanics—that you
can use in calculations. A list of all these constants can be
found in “Physical Constants” on page R-16.
To access the menu of physical constants:
1. Press .
2. Press .
hp40g+.book Page 25 Friday, December 9, 2005 1:03 AM
13-26 Using mathematical functions
3. Use the arrow keys to navigate through the options.
4. To see the symbol and value of a selected constant,
press . (Click to close the information
window that appears.)
The following example shows the information
available about the speed of light (one of the physics
constants).
5. To use the selected constant in a calculation, press
. The constant appears at the position of the
cursor on the edit line.
Example
Suppose you want to know the potential energy of a mass
of 5 units according to the equation .
1. Enter 5
2. Press and then press .
E
mc
2
=
hp40g+.book Page 26 Friday, December 9, 2005 1:03 AM
Using mathematical functions 13-27
3. Select light s...from the Physics menu.
4. Press . The menu closes and the value of the
selected constant is copied to the edit line.
5. Complete the equation as you would normally and
press to get the result.
hp40g+.book Page 27 Friday, December 9, 2005 1:03 AM
hp40g+.book Page 28 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-1
14
Computer Algebra System (CAS)
What is a CAS?
A computer algebra system (hereafter CAS) enables you
to perform symbolic calculations. With a CAS you
manipulate mathematical equations and expressions in
symbolic form, rather than manipulating approximations
of the numerical quantities represented by those symbols.
In other words, a CAS works in exact mode, giving you
infinite precision. On the other hand, non-CAS
calculations, such as those performed in HOME view or
by an aplet, are numerical calculations and are limited by
the precision of the calculator (to 10
–12
in the case of the
HP 40gs).
For example, with Standard as your numerical format,
1/2 + 1/6 returns 0.6666666666667 if you are
working in the HOME screen; however, 1/2 + 1/6
returns 2/3 if you are working with CAS. HOME
calculations are restricted to approximate (or numeric)
mode, while CAS calculations always work in exact
mode (unless you specifically change the default CAS
modes).
Each mode has advantages and disadvantages. For
example, in exact mode there is no rounding error, but
some calculations will take much longer to complete and
require more memory than equivalent calculations in
numeric mode.
Performing symbolic calculations
You perform CAS calculations with a special tool known
as the Equation Writer. Some computer algebra
operations can also be done in the HOME screen, as
long as you take certain precautions (see “Using CAS
functions in HOME” on page 14-7). Moreover, some
computer algebra operations can only be done in the
HOME screen; for example, symbolic linear algebra
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
14-2 Computer Algebra System (CAS)
using vectors and matrices. (Vectors and matrices cannot
be entered using the Equation Writer).
To open the Equation
Writer, press the soft-
key on the menu bar of the
HOME screen.
The illustration at the right
shows an expression being
written in the Equation
Writer. The soft keys on the
menu bar provide access to
CAS functions and
commands.
To leave the Equation Writer, press to return to
the HOME screen. Note that expressions written in the
Equation Writer (and the results of evaluating an
expression) are not automatically copied to the HOME
history when you leave the Equation Writer. (You can,
however, manually copy them to HOME: see page 14-8).
CAS functions are described in detail in “CAS functions
in the Equation Writer” on page 14-9. Chapter 15,
“Equation Writer”, explains in detail how to enter an
expression in the Equation Writer and contains numerous
worked examples of CAS in operation.
An example
To give you an idea of how CAS works, let’s consider a
simple example. Suppose you want to convert C to the
form where C is and d is a whole
number.
1. Open the Equation Writer by pressing the soft-
key on the HOME screen.
2. Enter the expression for
C.
[Hint: use the keys on
the keyboard as you
would if entering the
expression in HOME. Press the key twice to select
the entire first term before entering the second term.]
d 5 245 20
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Computer Algebra System (CAS) 14-3
3. Press and to
select just the 20 in the
term.
4. Press the menu
key and choose FACTOR.
Then press .
Note that the FACTOR
function is added to the
selected term.
5. Press to factor
the selected term.
6. Press to select the
entire second term, and
then press to
simplify it.
7.Press
to select the 45
in the first term.
8. As you did earlier, press
the menu key and
choose FACTOR. Then
press and to
factor the selected term.
9. Press to select the
entire second term, and
then press to
simplify it.
20
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
14-4 Computer Algebra System (CAS)
10.Press three times to
select the entire
expression and then
press to simplify
it to the form required.
CAS variables
When you use the symbolic calculation functions, you are
working with symbolic variables (variables that do not
contain a permanent value). In the HOME screen, a
variable of this kind must have a name like S1…S5,
s1…s5, n1…n5, but not X, which is assigned to a real
value. (By default, X is assigned to 0). To store symbolic
expressions, you must use the variables E0, E1…E9.
In the Equation Writer, all the variables may, or may not
be, assigned. For example, X is not assigned to a real
value by default, so computing X + X will return 2X.
Moreover, Equation Writer variables can have long
names, like XY or ABC, unlike in HOME where implied
multiplication is assumed. (For example ABC is
interpreted as A × B × C in HOME.) For these reasons,
variables used in the Equation Writer cannot be used in
HOME, and vice versa.
Using the PUSH command, you can transfer expressions
from the HOME screen history to CAS history (see
page 14-8). Likewise, you can use the POP command to
transfer expressions from CAS history to the HOME
screen history (see page 14-8).
The current variable
In the Equation Writer, the current variable is the name of
the symbolic variable contained in VX. It is almost always
X. (The current variable is always S1 in HOME.)
Some CAS functions depend on a current variable; for
example, the function DERVX calculates the derivative
with respect to the current variable. Hence in the Equation
Writer, DERVX(2*X+Y) returns 2 if VX = X, but 1 if VX
= Y. However, in the HOME screen, DERVX(2*S1+S2)
returns 2, but DERIV(2*S1+S2,S2) returns 1.
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-5
CAS modes
The modes that determine
how CAS operates can be
set on CAS MODES screen.
To display CAS MODES
screen, press:
·To navigate through the options in CAS MODES screen,
press the arrow keys.
To select or deselect a mode, navigate to the appropriate
field and press until the correct setting is displayed
(indicated by a check mark in the field). For some settings
(such as
INDEP VAR and MODULO), you will need to press
to be able to change the setting.
Press to close CAS MODES screen.
NOTE
You can also set CAS modes from within the Equation
Writer. See “Configuration menus” on page 15-3 for
information.
Selecting the
independent
variable
Many of the functions provided by CAS use a pre-
determined independent variable. By default, that
variable is the letter X (upper case) as shown in CAS
MODES screen above. However, you can change this
variable to any other letter, or combination of letters and
numbers, by editing the
INDEP VAR field in CAS MODES
screen. To change the setting, press , enter a new
value and then press .
The variable VX in the calculator's {HOME CASDIR}
directory takes, by default, the value of 'X'. This is the
name of the preferred independent variable for algebraic
and calculus applications. If you use another independent
variable name, some functions (for example, HORNER)
will not work properly.
Selecting the
modulus
The MODULO option on CAS MODES screen lets you
specify the modulo you want to use in modular arithmetic.
The default value is 13.
Approximate vs.
Exact mode
When the APPROX mode is selected, symbolic operations
(for example, definite integrals, square roots, etc.), will be
calculated numerically. When this mode is unselected,
exact mode is active, hence symbolic operations will be
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
14-6 Computer Algebra System (CAS)
calculated as closed-form algebraic expressions,
whenever possible. [Default: unselected.]
Num. Factor mode When the NUM FACTOR setting is selected, approximate
roots are used when factoring. For example,
is irreducible over the integers but has approximate roots
over the reals. With
NUM FACTOR set, the approximate roots
are returned. [Default: unselected.]
Complex vs. Real
mode
When COMPLEX is selected and an operation results in a
complex number, the result will be shown in the form a +
bi or in the form of an ordered pair (a,b). If
COMPLEX mode
is not selected and an operation results in a complex
number, you will be asked to switch to
COMPLEX mode. If
you decline, the calculator will report an error. [Default:
unselected.]
When in
COMPLEX mode, CAS is able to perform a wider
range of operations than in non-complex (or real) mode,
but it will also be considerably slower. Thus, it is
recommended that you don’t select
COMPLEX mode unless
requested by the calculator in the performance of a
particular operation.
Verbose vs. non-
verbose mode
When VERBOSE is selected, certain calculus applications
are provided with comment lines in the main display. The
comment lines will appear in the top lines of the display,
but only while the operation is being calculated. [Default:
unselected.]
Step-by-step mode When STEP/STEP is selected, certain operations will be
shown one step at a time in the display. You press
to show each step in turn. [Default: selected.]
Increasing-powers
mode
When INCR POW is selected, polynomials will be listed so
that the terms will have increasing powers of the
independent variable (which is the opposite to how
polynomials are normally written). [Default: unselected.]
Rigorous setting When RIGOROUS is selected, any algebraic expression of
the form |X|, i.e., the absolute value of X, is not
simplified to X. [Default: selected.]
Simplify non-
rational setting
When SIMP NON-RATIONAL is selected, non-rational
expressions will be automatically simplified. [Default:
selected.]
x
5
5x 1++
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Computer Algebra System (CAS) 14-7
Using CAS functions in HOME
You can use many computer algebra functions directly in
the HOME screen, as long as you take certain
precautions. CAS functions that take matrices as an
argument work only from HOME.
CAS functions can be accessed by pressing when
MATH menu is displayed. You can also directly type a
function name when you are in alpha mode.
Note that certain calculations will be performed in
approximate mode because numbers are interpreted as
reals instead of integers in HOME. To do exact
calculations, you should use the XQ command. This
command converts an approximate argument into an
exact argument.
For example, if Radians is your angle setting, then:
ARG(XQ(1 + i)) = π/4 but
ARG(1 + i) = 0.7853...
Similarly:
FACTOR(XQ(45)) = 3
2
× 5 but
FACTOR(45) = 45
Note too that the symbolic HOME variable S1 serves as
the current variable for CAS functions in HOME. For
example:
DERVX(S1
2
+ 2 × S1) = 2 × S1 + 2
The result 2 × S1 + 2 does not depend on the Equation
Writer variable, VX.
Some CAS functions cannot work in HOME because they
require a change to the current variable.
Remember that you must use S1,S2,…S5, s1,s2,…s5,
and n1,n2,…n5 for symbolic variables and E0, E1,…E9
to store symbolic expressions. For example, if you type:
S1
2
– 4 × S2 E1
then you get:
DERVX(E1) = S1 × 2
DERIV(E1, S2) = –4
INTVX(E1) = 1/3 S1
3
– 4 × (S2 × S1)
hp40g+.book Page 7 Friday, December 9, 2005 1:03 AM
14-8 Computer Algebra System (CAS)
Symbolic matrices are stored as a list of lists and therefore
must be stored in L0, L1…L9 (whereas numeric matrices
are stored in M0, M1,…M9). CAS linear algebra
instructions accept lists of lists as input.
For example, if you type in HOME:
XQ({{S2 + 1, 1}, { , 1}}) L1
then you have:
TRAN(L1) = {{S2 + 1, }, {1, 1}}
Some numeric linear algebra commands do not directly
work on a list of lists, but will do so after a conversion by
AXL. For example, if you enter:
DET(AXL(L1)) E1
you get:
S2–(–1 + )
Send expressions
from HOME to CAS
history
In the HOME screen, you can use the PUSH command to
send expressions to CAS history. For example, if you
enter PUSH(S1+1), S1+1 is written to CAS history.
Send expressions
from CAS to HOME
history
In the HOME screen, you can use the POP command to
retrieve the last expression written to CAS history. For
example, if S1+1 is the last expression written to CAS
history and you enter POP in the HOME screen, S1+1 is
written to the HOME screen history (and S1+1 is removed
from CAS history).
Online Help
When you are working with
the Equation Writer, you can
display online help about
any CAS command. To
display the contents of the
online help, press 2.
Press to navigate to the
command you want help
with and then press .
You can also get CAS help
from the HOME screen. Type
2
2
2
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-9
HELP and press . The menu of help topics
appears.
Each help topic includes the required syntax, along with
real sample values. You can copy the syntax, with the
sample values, to the HOME screen or to the Equation
Writer, by pressing .
TIP
If you highlight a CAS command and then press
2, help about the highlighted command is displayed.
You can display the online help in French rather than
English. For instructions, see “Online Help language” on
page 15-4.
CAS functions in the Equation Writer
You can display a menu of CAS functions in four ways:
by displaying the MATH menu from HOME and then
pressing , or
opening the Equation Writer and pressing ,
opening the Equation Writer and selecting a function
from a soft-key menu, or
opening the Equation Writer and pressing
.
You can also directly type the name of a CAS function
when you are in ALPHA mode.
Note that in this section, CAS functions available from the
sot-key menus in the Equation Writer are described. CAS
functions available from the MATH menu are described in
“CAS Functions on the MATH menu” on page 14-45.
NOTE
When using CAS, you should be aware that the required
syntax will vary depending on whether you are applying
the command to an expression or a function. All CAS
commands are designed to work with expressions; that is,
they take expressions as arguments. If you are going to
use a function—for example, F—you need to specify an
expression made from this function, such as F(x), where x
is the independent variable.
hp40g+.book Page 9 Friday, December 9, 2005 1:03 AM
14-10 Computer Algebra System (CAS)
For example, suppose you have stored the expression x
2
in G, and have defined the function F(x) as x
2
. Suppose
now you want to calculate INTVX(X
2
). You could:
enter INTVX(X
2
) directly, or
enter INTVX(G), or
enter INTVX(F(X)).
Note that you can apply the command directly to an
expression or to a variable that holds an expression (the
first two cases above). But where you want to apply it to
a defined function, you need to specify the full function
name, F(X), as in the third case above.
ALGB menu
COLLECT Factors over the integers
COLLECT combines like terms and factors the expression
over the integers.
Example
To factor over the integers you would type:
COLLECT(X
2
–4)
which gives in real mode:
Example
To factor over the integers you would type:
COLLECT(X
2
–2)
which gives:
DEF Define a function
For its argument, DEF takes an equality between:
1. the name of a function (with parentheses containing
the variable), and
2. an expression defining the function.
DEF defines this function and returns the equality.
x
2
4
x 2+()x 2()
x
2
2
x
2
2
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Computer Algebra System (CAS) 14-11
Typing:
DEF(U(N) = 2N+1)
produces the result:
U(N) = 2N+1
Typing:
U(3)
then returns:
7
Example
Calculate the first six Fermat numbers F1...F6 and
determine whether they are prime.
So, you want to calculate:
for k = 1...6
Typing the formula:
gives a result of 17. You can then invoke the
ISPRIME?() command, which is found in the MATH
key’s Integer menu. The response is 1, which means
TRUE. Using the history (which you access by pressing the
SYMB key), you put the expression into the
Equation Writer with ECHO, and change it to:
Or better, define a function F(K) by selecting DEF from the
ALGB menu on the menu bar and type:
The response is and F is now listed amongst the
variables (which you can verify using the VARS key).
For K=5, you then type:
F(5)
Fk() 2
2
k
1+=
2
2
2
1+
2
2
2
1+
2
2
3
1+
DEFFK() 2
2
k
1+=()
2
2
k
1+
hp40g+.book Page 11 Friday, December 9, 2005 1:03 AM
14-12 Computer Algebra System (CAS)
which gives
4294967297
You can factor F(5) with FACTOR, which you’ll find in the
ALGB menu on the menu bar.
Typing:
FACTOR(F(5))
gives:
641·6700417
Typing:
F(6)
gives:
18446744073709551617
Using FACTOR to factor it, then yields:
274177·67280421310721
EXPAND Distributivity
EXPAND expands and simplifies an expression.
Example
Typing:
gives:
FACTOR Factorization
FACTOR factors an expression.
Example
To factor:
type:
FACTOR(X
4
+1)
FACTOR is located in the ALGB menu.
XPAND X
2
2 X 1++()X
2
2 X 1+(
)
(
x
4
1+
x
4
1+
hp40g+.book Page 12 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-13
In real mode, the result is:
In complex mode (using CFG), the result is:
PARTFRAC Partial fraction expansion
PARTFRAC has a rational fraction as an argument.
PARTFRAC returns the partial fraction decomposition of
this rational fraction.
Example
To perform a partial fraction decomposition of a rational
function, such as:
you use the PARTFRAC command.
In real and direct mode, this produces:
In complex mode, this produces:
QUOTE Quoted expression
QUOTE(expression) is used to prevent an expression
from being evaluated or simplified.
Example 1
Typing:
gives:
+
x
2
2 x 1++()x
2
2 x 1+()
1
16
------
2x 1 i+()2+()2x 1 i+()–2()2x 1 i()+2()
2x 1 i()–2()
⋅⋅
x
5
2 x
3
1+
x
4
2 x
3
2+ x
2
2 x 1+()
-------------------------------------------------------------------------
x 2
x 3
2 x
2
2+
----------------------
1
2 x 2
-------------------
++ +
x 2
13i
4
--------------
xi+
--------------
1
2
------
x 1
-----------
13i+
4
--------------
xi
--------------
++ + +
i
m QUOTE 2X 1()( EXP(
1
X
---
1 ) X +=,
hp40g+.book Page 13 Friday, December 9, 2005 1:03 AM
14-14 Computer Algebra System (CAS)
Example 2
Typing:
SUBST(QUOTE(CONJ(Z)),Z=1+i)
gives:
CONJ(1+i)
STORE Store an object in a variable
STORE stores an object in a variable.
STORE is found in the ALGB menu or the Equation Writer
menu bar.
Example
Type:
STORE(X
2
-4,ABC)
or type:
X
2
-4
then select it and call STORE, then type ABC, then press
ENTER to confirm the definition of the variable ABC.
To clear the variable, press VARS in the Equation Writer
(then choose PURGE on the menu bar), or select
UNASSIGN on the ALGB menu by typing, for example,
UNASSIGN(ABC)
| Substitute a value for a variable
| is an infix operator used to substitute a value for a
variable in an expression (similar to the function SUBST).
| has two parameters: an expression dependent on a
parameter, and an equality (parameter=substitute value).
| substitutes the specified value for the variable in the
expression.
Typing:
gives:
X
2
1
X 2=
2
2
1
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Computer Algebra System (CAS) 14-15
SUBST Substitute a value for a variable
SUBST has two parameters: an expression dependent on
a parameter, and an equality (parameter=substitute
value).
SUBST substitutes the specified value for the variable in
the expression.
Typing:
SUBST(A
2
+1,A=2)
gives:
TEXPAND Develop in terms of sine and cosine
TEXPAND has a trigonometric expression or
transcendental function as an argument.
TEXPAND develops this expression in terms of sin(x) and
cos(x).
Example
Typing:
TEXPAND(COS(X+Y))
gives:
Example
Typing:
TEXPAND(COS(3·X))
gives:
UNASSIGN Clear a variable
UNASSIGN is used to clear a variable, for example:
UNASSIGN(ABC)
2
2
1+
y()cos x()cos y() x()sinsin
4 x()
3
cos 3 x()cos⋅⋅
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14-16 Computer Algebra System (CAS)
DIFF menu
DERIV Derivative and partial derivative
DERIV has two arguments: an expression (or a function)
and a variable.
DERIV returns the derivative of the expression (or the
function) with respect to the variable given as the second
parameter (used for calculating partial derivatives).
Example
Calculate:
Typing:
DERIV(X·Y
2
·Z
3
+ X·Y,Z)
gives:
DERVX Derivative
DERVX has one argument: an expression. DERVX
calculates the derivative of the expression with respect to
the variable stored in VX.
For example, given:
calculate the derivative of f.
Type:
Or, if you have stored the definition of f(x) in F, that is, if
you have typed:
then type:
xy
2
z
3
⋅⋅ xy+()
z
----------------------------------------------
3 xy
2
z
2
⋅⋅
fx()
x
x
2
1
--------------
x 1+
x 1
------------
⎝⎠
⎛⎞
ln+=
D
ERVX
X
X
2
1
---------------
LN
X 1+
X 1
-------------
+
TORE
X
X
2
1
---------------
LN
X 1+
X 1
-------------
⎝⎠
⎛⎞
F,+
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Computer Algebra System (CAS) 14-17
DERVX(F)
Or, if you have defined F(X) using DEF, that is, if you have
typed:
then type:
DERVX(F(X))
Simplify the result to get:
DIVPC Division in increasing order by exponent
DIVPC has three arguments: two polynomials A(X) and
B(X) (where B(0)
0), and a whole number n.
DIVPC returns the quotient Q(X) of the division of A(X) by
B(X), in increasing order by exponent, and with deg(Q)
<= n or Q = 0.
Q[X] is then the limited nth-order expansion of:
in the vicinity of X= 0.
Typing:
DIVPC(1+X
2
+X
3
,1+X
2
,5)
gives:
NOTE:
When the calculator displays a request to change to
increasing powers mode, respond yes.
FOURIER Fourier coefficients
FOURIER has two parameters: an expression f(x) and a
whole number N.
FOURIER returns the Fourier coefficient c
N
of f(x),
considered to be a function defined over interval [0, T]
D
EF(F(X)
X
X
2
1
---------------
LN
X 1+
X 1
-------------
⎝⎠
⎛⎞
+=
3 x
2
1
x
4
2 x
2
1+
---------------------------------
AX[]
BX[]
------------
1 x
3
x
5
+
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14-18 Computer Algebra System (CAS)
and with period T (T being equal to the contents of the
variable PERIOD).
If f(x) is a discrete series, then:
Example
Determine the Fourier coefficients of a periodic function f
with period 2π and defined over interval [0, 2π] by
f(x)=x
2
.
Typing:
STORE(2π,PERIOD)
FOURIER(X
2
,N)
The calculator does not know that N is a whole number,
so you have to replace EXP(2 iN∗π) with 1 and then
simplify the expression. We get
So if , then:
Typing:
FOURIER(X
2
,0)
gives:
so if , then:
IBP Partial integration
IBP has two parameters: an expression of the form
and .
f
x() c
N
e
2iNxπ
T
----------------
N =
+
=
2 iNπ 2+⋅⋅
N
2
----------------------------------
N 0
c
N
2 iNπ 2+⋅⋅
N
2
----------------------------------
=
4 π
2
3
-------------
N 0=
c
0
4 π
2
3
-------------
=
ux() v' x() vx()
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Computer Algebra System (CAS) 14-19
IBP returns the AND of and of
that is, the terms that are calculated when performing a
partial integration.
It remains then to calculate the integral of the second term
of the AND, then add it to the first term of the AND to
obtain a primitive of .
Typing:
IBP(LN(X),X)
gives:
X·LN(X) AND - 1
The integration is completed by calling INTVX:
INTVX(X·LN(X)AND - 1)
which produces the result:
X·LN(X) - X
NOTE:
If the first IBP (or INTVX) parameter is an AND of two
elements, IBP concerns itself only with the second element
of the AND, adding the integrated term to the first element
of the AND (so that you can perform multiple IBP in
succession).
INTVX Primitive and defined integral
INTVX has one argument: an expression.
INTVX calculates a primitive of its argument with respect
to the variable stored in VX.
Example
Calculate a primitive of sin(x) × cos(x).
Typing:
INTVX(SIN(X)·COS(X))
gives in step-by-step mode:
COS(X)·SIN(X)
Int[u’F(u)] with u=SIN(X)
Pressing OK then sends the result to the Equation Writer:
ux() vx() v x() u' x()
ux() v' x()
x()
2
sin
2
------------------
hp40g+.book Page 19 Friday, December 9, 2005 1:03 AM
14-20 Computer Algebra System (CAS)
Example
Given:
calculate a primitive of f.
Type:
Or, if you have stored f(x) in F, that is, if you have already
typed:
then type:
INTVX(F)
Or, if you have used DEF to define f(x), that is, if you have
already typed:
then type:
INTVX(F(X))
The result in all cases is equivalent to:
You will obtain absolute values only in Rigorous mode.
(See “CAS modes” on page 14-5 for instructions on
setting and changing modes.)
Example
Calculate:
Typing:
f
x()
x
x
2
1
--------------
LN
x 1+
x 1
------------
⎝⎠
⎛⎞
+=
N
TVX
X
X
2
1+
---------------
LN
X 1+
X 1
-------------
⎝⎠
⎛⎞
+
TORE
X
X
2
1
---------------
LN
X 1+
X 1
-------------
⎝⎠
⎛⎞
F,+
D
EF(F(X)
X
X
2
1
---------------
LN
X 1+
X 1
-------------
⎝⎠
⎛⎞
+=
X
LN
X 1+
X 1
-------------
⎝⎠
⎛⎞
3
2
---
LN X 1()
3
2
---
LN X 1+(++
2
x
6
2+ x
4
x
2
+
-----------------------------------
xd
hp40g+.book Page 20 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-21
gives a primitive:
Note
You can also type which gives the
primitive which is zero for x = 1
Example
Calculate:
Typing:
gives the result:
NOTE:
If the argument to INTVX is the AND of two elements,
INTVX concerns itself only with the second element of the
AND, and adds the result to the first argument.
lim Calculate limits
LIMIT or lim has two arguments: an expression dependent
on a variable, and an equality (a variable = the value to
which you want to calculate the limit).
You can omit the name of the variable and the sign =,
when this name is in VX).
It is often preferable to use a quoted expression:
NTVX
2
X
6
2 X
4
X
2
++
--------------------------------------
3 x()atan
2
x
---
x
x
2
1+
--------------
2
X
6
2+ X
4
X
2
+
--------------------------------------
X
d
1
X
3 x()atan
2
x
---
x
x
2
1+
--------------
3 π 10+
4
-----------------------
+
⎝⎠
⎛⎞
1
x()sin 2 x()sin+
--------------------------------------------
xd
N
TVX
1
SIN X() SIN 2 X()+
----------------------------------------------------
1
6
---
LN X()cos 1()
1
2
---
LN X()cos 1+()
2
3
------
LN 2 X()cos 1+()
++
hp40g+.book Page 21 Friday, December 9, 2005 1:03 AM
14-22 Computer Algebra System (CAS)
QUOTE(expression), to avoid rewriting the expression in
normal form (i.e., not to have a rational simplification of
the arguments) during the execution of the LIMIT
command.
Example
Typing:
gives:
+
To find a right limit, for example, type:
gives (if X is the current variable):
+
To find a left limit, for example, type:
gives (if X is the current variable):
It is not necessary to quote the second argument when it
is written with =, for example:
gives:
+
Example
For n > 2 in the following expression, find the limit as x
approaches 0:
You can use the LIMIT command to do this.
lim QUOTE 2X 1()(( EXP
1
X 1
------------
⎝⎠
⎛⎞
X += ),
lim
1
X 1
------------
QUOTE 1 0+(),
⎝⎠
⎛⎞
lim
1
X 1
------------
QUOTE 1 0(),
⎝⎠
⎛⎞
lim
1
X 1
------------
X 10+=(),
⎝⎠
⎛⎞
nx()tan nx
()tan
nx()sin nx()sin
----------------------------------------------------
hp40g+.book Page 22 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-23
Typing:
gives:
2
NOTE: To find the limit as x approaches a
+
(resp a
), the
second argument is written:
X=A+0(resp X=A-0)
For the following expression, find the limit as x
approaches +:
Typing:
produces (after a short wait):
NOTE: the symbol is obtained by typing SHIFT 0.
To obtain –:
(–)
To obtain +:
(–)(–)
You can also find the symbol in the MATH key’s
Constant menu.
PREVAL Evaluate a primitive
PREVAL has three parameters: an expression F(VX)
dependent on the variable contained in VX, and two
expressions A and B.
For example, if VX contains X, and if F is a function,
PREVAL (F(X),A,B) returns F(B)-F(A).
lim
NTANX() TAN N X)(
SIN N X()NSINX()
-----------------------------------------------------------------
0,
⎝⎠
⎛⎞
xxx++ x
lim XXX++ X +,
⎝⎠
⎛⎞
1
2
---
hp40g+.book Page 23 Friday, December 9, 2005 1:03 AM
14-24 Computer Algebra System (CAS)
PREVAL is used for calculating an integral defined from a
primitive: it evaluates this primitive between the two limits
of the integral.
Typing:
PREVAL(X
2
+X,2,3)
gives:
6
RISCH Primitive and defined integral
RISCH has two parameters: an expression and the name
of a variable.
RISCH returns a primitive of the first parameter with
respect to the variable specified in the second parameter.
Typing:
RISCH((2·X
2
+1)·EXP(X
2
+1),X)
gives:
X·EXP(X
2
+1)
NOTE:
If the RISCH parameter is the AND of two elements,
RISCH concerns itself only with the second element of the
AND, and adds the result to the first argument.
SERIES Limited
n
th-order expansion
SERIES has three arguments: an expression dependent on
a variable, an equality (the variable x = the value a to
which you want to calculate the expansion) and a whole
number (the order n of the limited expansion).
You can omit the name of the variable and the = sign
when this name is in VX).
SERIES returns the limited nth-order expansion of the
expression in the vicinity of x = a.
Example — Expansion in the vicinity of x=a
Give a limited 4th-order expansion of cos(2 · x)
2
in the
vicinity of .
For this you use the SERIES command.
x
π
6
---
=
hp40g+.book Page 24 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-25
Typing:
gives:
Example — Expansion in the vicinity of x=+
or x=–
Example 1
Give a 5th-order expansion of arctan(x) in the vicinity of
x=+, taking as infinitely small .
Typing:
SERIES(ATAN(X),X =+,5)
gives:
Example 2
Give a 2nd-order expansion of in the
vicinity of x=+∞, taking as infinitely small .
gives:
Unidirectional expansion
To perform an expansion in the vicinity of x = a where
x > a, use a positive real (such as 4.0) for the order.
To perform an expansion in the vicinity of x = a where
x < a, use a negative real (such as –4.0) for the order.
S
ERIES COS 2 X()
2
X
π
6
---
=4,,
1
4
---
3h 2h
2 83
3
----------
h
3 8
3
---
h
4
0
h
5
4
-----
⎝⎠
⎛⎞
+++
hX
π
6
---
=
〈|
h
1
x
---
=
π
2
---
h
h
3
3
-----
h
5
5
-----
0
π h
6
2
-------------
⎝⎠
⎛⎞
++
h
1
x
---
=
2x 1()e
1
x 1
-----------
h
1
x
---
=
S
ERIES 2X 1 )(( EXP
1
X 1
------------
⎝⎠
⎛⎞
X +3
)
,=,
12 6h 12h
2
17h
3
++ +
6 h
-------------------------------------------------------
02 h
3
()+
h
1
x
---
=
hp40g+.book Page 25 Friday, December 9, 2005 1:03 AM
14-26 Computer Algebra System (CAS)
You must be in Rigorous (not Sloppy) mode to apply
SERIES with unidirectional expansion. (See “CAS modes”
on page 14-5 for instructions on setting and changing
modes.
Example 1
Give a 3rd-order expansion of in the vicinity of
x = 0
+
.
Typing:
gives:
Example 2
Give a 3rd-order expansion of in the vicinity of
x = 0
.
Typing:
gives:
Note that h = –x is positive as x 0
.
Example 3
If you enter the order as an integer rather than a real, as
in:
you will get the following error:
SERIES Error: Unable to find sign.
Note that if you had been in Sloppy rather than Rigorous
mode, all three examples above would have returned the
same answer as you got when exploring in the vicinity of
x = 0
+
:
x
2
x
3
+
SERIES X
2
X
3
+ X 03.0,=,()
1
16
------
h
4
1
8
------
h
3
1
2
---
h
2
h+++0h
5
()+ hx=()
x
2
x
3
+
S
ERIES X
2
X
3
+ X 03.0,=,(
)
1
16
------
h
4
1
8
------
h
3
1
2
------
h
2
h 0 h
5
()++++hx=()
SERIES X
2
X
3
+ X 03,=,()
hp40g+.book Page 26 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-27
TABVAR Variation table
TABVAR has as a parameter an expression with a
rational derivative.
TABVAR returns the variation table for the expression in
terms of the current variable.
Typing:
TABVAR(3X
2
-8X-11)
gives, in step-by-step mode:
Variation table:
The arrows indicate whether the function is increasing or
decreasing during the specified interval. This particular
variation table indicates that the function F(x) decreases
for x in the interval [–, ], reaching a minimum of
at x = . It then increases in the interval [ , +], reaching
a maximum of +.
Note that “?” appearing in the variation table indicates
that the function is not defined in the corresponding
interval.
TAYLOR0 Limited expansion in the vicinity of 0
TAYLOR0 has a single argument: the function of x to
expand. It returns the function’s limited 4th-relative-order
expansion in the vicinity of x=0 (if x is the current
variable).
1
16
------
h
4
1
8
------
h
3
1
2
---
h
2
h+++0h
5
()+ hx=()
++ X
+
↓↑
+ F
F 3 x
2
8 x–11()=
F'32x 8⋅⋅()=
23x 4()()
4
3
---
49
3
----------
4
3
---
49
3
----------
4
3
---
4
3
---
hp40g+.book Page 27 Friday, December 9, 2005 1:03 AM
14-28 Computer Algebra System (CAS)
Typing:
gives:
Note
‘th-order’ means that the numerator and the denominator
are expanded to the 4th relative order (here, the 5th
absolute order for the numerator, and for the
denominator, which is given in the end, the 2nd order (5
3), seeing that the exponent of the denominator is 3).
TRUNC Truncate at order n - 1
TRUNC enables you to truncate a polynomial at a given
order (used to perform limited expansions).
TRUNC has two arguments: a polynomial and X
n
.
TRUNC returns the polynomial truncated at order n1;
that is, the returned polynomial has no terms with
exponents n.
Typing:
gives:
REWRI menu
The REWRI menu contains functions that enable you to
rewrite an expression in another form.
DISTRIB Distributivity of multiplication
DISTRIB enables you to apply the distributivity of
multiplication in respect to addition in a single instance.
DISTRIB enables you, when you apply it several times, to
carry out the distributivity step by step.
TAYLOR0
TAN P X()SIN P X()
TAN Q X()SIN Q X()
----------------------------------
⎝⎠
⎛⎞
P
3
Q
3
-
-----
P
5
Q
2
P
3
4 Q
3
-----------------------------
x
2
+
TRUNC 1 X
1
2
-++ X
2
⎝⎠
⎛⎞
3
X
4
,
⎝⎠
⎛⎞
4x
3 9
2
---
x
2
3x 1+++
hp40g+.book Page 28 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-29
Typing:
DISTRIB((X+1)·(X+2)·(X+3))
gives:
EPSX0 Disregard small values
EPSX0 has as a parameter an expression in X, and returns
the same expression with the values less than EPS
replaced by zeroes.
Typing:
EPSX0(0.001 + X)
gives, if EPS=0.01:
0 + x
or, if EPS=0.0001:
.001 + x
EXPLN Transform a trigonometric expression into complex
exponentials
EXPLN takes as an argument a trigonometric expression.
It transforms the trigonometric function into exponentials
and logarithms without linearizing it.
EXPLN puts the calculator into complex mode.
Typing:
EXPLN(SIN(X))
gives:
EXP2POW Transform exp(nln(x)) as a power of x
EXP2POW transforms an expression of the form
exp(n × ln(x)), rewriting it as a power of x.
xx2+()x 3+()⋅⋅ 1+ x 2+()x 3+()⋅⋅
ix()exp
1
ix()exp
-----------------------
2 i
-
---------------------------------------------------
hp40g+.book Page 29 Friday, December 9, 2005 1:03 AM
14-30 Computer Algebra System (CAS)
Typing:
EXP2POW(EXP(N · LN(X)))
gives:
FDISTRIB Distributivity
FDISTRIB has an expression as argument.
FDISTRIB enables you to apply the distributivity of
multiplication with respect to addition all at once.
Typing:
FDISTRIB((X+1)·(X+2)·(X+3))
gives:
x·x·x + 3·x·x + x·2·x + 3·2·x + x·x·1 + 3·x·1 + x·2·1
+ 3·2·1
After simplification (by pressing ENTER):
x
3
+ 6·x
2
+ 11·x + 6
LIN Linearize the exponentials
LIN has as an argument an expression containing
exponentials and trigonometric functions. LIN does not
linearize trigonometric expressions (as does TLIN) but
converts a trigonometric expression to exponentials and
then linearizes the complex exponentials.
LIN puts the calculator into complex mode when dealing
with trigonometric functions.
Example 1
Typing:
LIN((EXP(X)+1)
3
)
gives:
3·exp(x) + 1 + 3·exp(2·x) + exp(3·x)
Example 2
Typing:
LIN(COS(X)
2
)
gives:
x
n
hp40g+.book Page 30 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-31
Example 3
Typing:
LIN(SIN(X))
gives:
LNCOLLECT Regroup the logarithms
LNCOLLECT has as an argument an expression
containing logarithms.
LNCOLLECT regroups the terms in the logarithms. It is
therefore preferable to use an expression that has already
been factored (using FACTOR).
Typing:
LNCOLLECT(LN(X+1)+LN(X-1))
gives:
ln((x+1)(x1))
POWEXPAND Transform a power
POWEXPAND writes a power in the form of a product.
Typing:
POWEXPAND((X+1)
3
)
gives:
(x+1) · (x+1) · (x+1)
This allows you to do the development of (x + 1)
3
in step
by step, using DISTRIB several times on the preceding
result.
SINCOS Transform the complex exponentials into sin and cos
SINCOS takes as an argument an expression containing
complex exponentials.
SINCOS then rewrites this expression in terms of sin(x)
and cos(x).
1
4
---
2 ix⋅⋅()()exp
1
2
---
1
4
---
2 ix⋅⋅()exp++
i
2
---
ixexp
i
2
---
ix()()exp+
hp40g+.book Page 31 Friday, December 9, 2005 1:03 AM
14-32 Computer Algebra System (CAS)
Typing:
SINCOS(EXP(i·X))
gives after turning on complex mode, if necessary:
cos(x) + i · sin(x)
SIMPLIFY Simplify
SIMPLIFY simplifies an expression automatically.
Typing:
gives, after simplification:
4 · cos(x)
2
2
XNUM Evaluation of reals
XNUM has an expression as a parameter.
XNUM puts the calculator into approximate mode and
returns the numeric value of the expression.
Typing:
XNUM(2)
gives:
1.41421356237
XQ Rational approximation
XQ has a real numeric expression as a parameter.
XQ puts the calculator into exact mode and gives a
rational or real approximation of the expression.
Typing:
XQ(1.41421)
gives:
SIMPLIFY
SIN 3 X()SIN 7 X()+
SIN 5 X()
-----------------------------------
⎝⎠
⎛⎞
66441
46981
---------------
hp40g+.book Page 32 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-33
Typing:
XQ(1.414213562)
gives:
2
SOLV menu
The SOLV menu contains functions that enable you to
solve equations, linear systems, and differential
equations.
DESOLVE Solve differential equations
DESOLVE enables you to solve differential equations. (For
linear differential equations having constant coefficients,
it is better to use LDEC.)
DESOLVE has two arguments:
1. the differential equation where is written as d1Y(X)
(or the differential equation and the initial conditions
separated by AND),
2. the unknown Y(X).
The mode must be set to real.
Example 1
Solve:
y” + y = cos(x)
y(0)=c
0
y’(0) =c
1
Typing:
DESOLVE(d1d1Y(X)+Y(X) = COS(X),Y(X))
gives:
cC0 and cC1 are integration constants (y(0) = cC0 y’(0)
= cC1).
You can then assign values to the constants using the
SUBST command.
y'
YX() cC0 x()cos
x 2 cC1+
2
--------------------------
x()sin+=
hp40g+.book Page 33 Friday, December 9, 2005 1:03 AM
14-34 Computer Algebra System (CAS)
To produce the solutions for y(0) = 1, type:
which gives:
Example 2
Solve:
y” + y = cos(x)
y(0) = 1 y’(0) = 1
It is possible to solve for the constants from the outset.
Typing:
DESOLVE((d1d1Y(X)+Y(X)=COS(X))
AND (Y(0)=1) AND (d1Y(0)=1),Y(X))
gives:
ISOLATE The zeros of an expression
ISOLATE returns the values that are the zeros of an
expression or an equation.
ISOLATE has two parameters: an expression or equation,
and the name of the variable to isolate (ignoring
REALASSUME).
Typing:
ISOLATE(X
4
-1=3,X)
gives in real mode:
(x = 2) OR (x = −√2)
and in complex mode:
(x = 2 · i) OR (x = −√2) OR
(x = (2 · i)) OR (x = 2)
S
UBST Y X()(
c
C0 COS X()
X2+cC1
2
----------------+ SIN X()cC0, 1 )
=
=
yx()
2 x()cos x 2+ cC1()+ x()sin
2
----------------------------------------------------------------------------------
=
Yx() xcos
2 x+
2
------------
+ x()sin=
hp40g+.book Page 34 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-35
LDEC Linear differential equations having constant
coefficients
LDEC enables you to directly solve linear differential
equations having constant coefficients.
The parameters are the second member and the
characteristic equation.
Solve:
y” 6 · y’ + 9 · y = x · e
3·x
Typing:
LDEC(X·EXP(3·X),X
2
6·X+9)
gives:
cC0 and cC1 are integration constants (y(0) = cC0 and
y’(0) = cC1).
LINSOLVE Solve linear system
LINSOLVE enables you to solve a system of linear
equations.
It is assumed that the various equations are of the form
expression = 0.
LINSOLVE has two arguments: the first members of the
various equations separated by AND, and the names of
the various variables separated by AND.
Example 1
Typing:
LINSOLVE(X+Y+3 AND X-Y+1, X AND Y)
gives:
(x = 2) AND (y = 1)
or, in Step-by-step mode (CFG, etc.):
L2=L2L1
ENTER
-
18 x 6()cC06xcC1⋅⋅ x
3
+()
6
-----------------------------------------------------------------------------------------
3 x()exp
⎝⎠
⎛⎞
113
11 1
hp40g+.book Page 35 Friday, December 9, 2005 1:03 AM
14-36 Computer Algebra System (CAS)
L1=2L1+L2
ENTER
Reduction Result
then press ENTER. The following is then written to the
Equation Writer:
(x = 2) AND (y = 1)
Example 2
Type:
(2·X+Y+Z=1)AND(X+Y+2·Z=1)AND(X+2·Y+Z=4)
Then, invoke LINSOLVE and type the unknowns:
X AND Y AND Z
and press the ENTER key.
The following result is produced if you are in Step-by-step
mode (CFG, etc.):
L2=2L2L1
ENTER
L3=2L3L1
and so on until, finally:
Reduction Result
11 3
02 2
20 4
02 2
211 1
112 1
121 4
211 1
013 1
121 4
80 0 4
08 0 20
00 8–4
hp40g+.book Page 36 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-37
then press ENTER. The following is then written to the
Equation Writer:
SOLVE Solve equations
SOLVE has as two parameters:
(1) either an equality between two expressions, or a
single expression (in which case = 0 is implied), and
(2) the name of a variable.
SOLVE solves the equation in R in real mode and in C in
complex mode (ignoring REALASSUME).
Typing:
SOLVE(X
4
-1=3,X)
gives, in real mode:
(x = −√2) OR (x = 2)
or, in complex mode:
(x = −√2) OR (x = 2) OR (x = i · 2) OR (x = i2)
Solve systems
SOLVE also enables you to solve a system of non-linear
equations, if they are polynomials. (If they are not
polynomials, use MSOLV in the HOME screen to get a
numerical solution.)
It is assumed that the various equations are of the form
expression = 0.
SOLVE has as arguments, the first members of the various
equations separated by AND, and the names of the
various variables separated by AND.
Typing:
SOLVE(X
2
+Y
2
-3 AND X-Y
2
+1,X AND Y)
gives:
(x = 1) AND (y = −√2) OR (x = 1) AND (y = 2)
x
1
2
---
=
⎝⎠
⎛⎞
AND y
5
2
---
=
⎝⎠
⎛⎞
AND z
1
2
---
=
⎝⎠
⎛⎞
hp40g+.book Page 37 Friday, December 9, 2005 1:03 AM
14-38 Computer Algebra System (CAS)
SOLVEVX Solve equations
SOLVEVX has as a parameter either:
(1) an equality between two expressions in the variable
contained in VX, or
(2) a single such expression (in which case = 0 is
implied).
SOLVEVX solves the equation.
Example 1
Typing:
SOLVEVX(X
4
-1=3)
gives, in real mode:
(x = −√2) OR (x = 2)
or, in complex mode, even if you have chosen X as real:
(x = −√2) OR (x = 2) OR (x = i · 2) OR (x = i2)
Example 2
Typing:
SOLVEVX(2X
2
+X)
gives, in real mode:
(x = −1/2) OR (x = 0)
TRIG menu
The TRIG menu contains functions that enable you to
transform trigonometric expressions.
ACOS2S Transform the arccos into arcsin
ACOS2S has as a trigonometric expression as an
argument.
ACOS2S transforms the expression by replacing
arccos(x) with arcsin(x).
π
2
---
hp40g+.book Page 38 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-39
Typing:
ACOS2S(ACOS(X) + ASIN(X))
gives, when simplified:
ASIN2C Transform the arcsin into arccos
ASIN2C has as a trigonometric expression as an
argument.
ASIN2C transforms the expression by replacing arcsin(x)
with arccos(x).
Typing:
ASIN2C(ACOS(X) + ASIN(X))
gives, when simplified:
ASIN2T Transform the arccos into arctan
ASIN2T has a trigonometric expression as an argument.
ASIN2T transforms the expression by replacing arcsin(x)
with
Typing:
ASIN2T(ASIN(X))
gives:
ATAN2S Transform the arctan into arcsin
ATAN2S has a trigonometric expression as an argument.
ATAN2S transforms the expression by replacing
arctan(x) with .
π
2
---
π
2
-----
π
2
-----
arc
x
1 x
2
------------------
⎝⎠
⎜⎟
⎛⎞
tan
x
1 x
2
------------------
⎝⎠
⎜⎟
⎛⎞
atan
arc
x
1 x
2
+
------------------
⎝⎠
⎜⎟
⎛⎞
sin
hp40g+.book Page 39 Friday, December 9, 2005 1:03 AM
14-40 Computer Algebra System (CAS)
Typing:
ATAN2S(ATAN(X))
gives:
HALFTAN Transform in terms of tan(x/2)
HALFTAN has a trigonometric expression as an
argument.
HALFTAN transforms sin(x), cos(x) and tan(x) in the
expression, rewriting them in terms of tan(x/2).
Typing:
HALFTAN(SIN(X)
2
+ COS(X)
2
)
gives (SQ(X) = X
2
):
or, after simplification:
1
SINCOS Transform the complex exponentials into sin and cos
SINCOS takes an expression containing complex
exponentials as an argument.
SINCOS then rewrites this expression in terms of sin(x)
and cos(x).
Typing:
SINCOS(EXP(i · X))
gives after turning on complex mode, if necessary:
cos(x) + i · sin(x)
TAN2CS2 Transform tan(x) with sin(2x) and cos(2x)
TAN2CS2 has a trigonometric expression as an
argument.
x
x
2
1+
------------------
⎝⎠
⎜⎟
⎛⎞
asin
2
x
2
---
⎝⎠
⎛⎞
tan
SQ
x
2
---
⎝⎠
⎛⎞
tan
⎝⎠
⎛⎞
1+
---------------------------------------
⎝⎠
⎜⎟
⎜⎟
⎜⎟
⎛⎞
2
1 SQ
x
2
---
⎝⎠
⎛⎞
tan
⎝⎠
⎛⎞
SQ
x
2
---
⎝⎠
⎛⎞
tan
⎝⎠
⎛⎞
1+
---------------------------------------
⎝⎠
⎜⎟
⎜⎟
⎜⎟
⎛⎞
2
+
hp40g+.book Page 40 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-41
TAN2CS2 transforms this expression by replacing tan(x)
with .
Typing:
TAN2CS2(TAN(X))
gives:
TAN2SC Replace tan(x) with sin(x)/cos(x)
TAN2SC has a trigonometric expression as an argument.
TAN2SC transforms this expression by replacing tan(x)
with .
Typing:
TAN2SC(TAN(X))
gives:
TAN2SC2 Transform tan(x) with sin(2x) and cos(2x)
TAN2SC2 has a trigonometric expression as an
argument.
TAN2SC2 transforms this expression by replacing tan(x)
with
Typing:
TAN2SC2(TAN(X))
gives:
TCOLLECT Reconstruct the sine and the cosine of the same angle
TCOLLECT has a trigonometric expression as an
argument.
12x()cos
2 x()sin
--------------------------------
12x()cos
2 x()sin
--------------------------------
x()sin
x()cos
----------------
x
()
s
i
n
x()cos
----------------
2 x()sin
12x()cos+
---------------------------------
2 x()sin
12x()cos+
---------------------------------
hp40g+.book Page 41 Friday, December 9, 2005 1:03 AM
14-42 Computer Algebra System (CAS)
TCOLLECT linearizes this expression in terms of sin(n x)
and cos(n x), then (in Real mode) reconstructs the sine and
cosine of the same angle.
Typing:
TCOLLECT(SIN(X) + COS(X))
gives:
TEXPAND Develop transcendental expressions
TEXPAND has as an argument a transcendental
expression (that is, an expression with trigonometric,
exponential or logarithmic functions). TEXPAND develops
this expression in terms of sin(x), cos(x), exp(x) or ln(x).
Example 1
Typing:
TEXPAND(EXP(X+Y))
gives:
exp(x)·exp(y)
Example 2
Typing:
TEXPAND(LN(X·Y))
gives:
ln(y) + ln(x)
Example 3
Typing:
TEXPAND(COS(X+Y))
gives:
cos(y)·cos(x)–sin(y)·sin(x)
Example 4
Typing:
TEXPAND(COS(3·X))
2 x
π
4
---
⎝⎠
⎛⎞
cos
hp40g+.book Page 42 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-43
gives:
4·cos(x)
3
–3·cos(x)
TLIN Linearize a trigonometric expression
TLIN has as an argument a trigonometric expression.
TLIN linearizes this expression in terms of sin(n x) and
cos(n x).
Example 1
Typing:
TLIN(COS(X) · COS(Y))
gives:
Example 2
Typing:
TLIN(COS(X)
3
)
gives:
Example 3
Typing:
TLIN(4·COS(X)
2
-2)
gives:
TRIG Simplify using sin(x)
2
+ cos(x)
2
= 1
TRIG has as an argument a trigonometric expression.
TRIG simplifies this expression using the identity
sin(x)
2
+cos(x)
2
= 1.
1
2
---
xy()cos
1
2
---
xy+()cos+
1
4
---
3 x()cos
3
4
---
x()cos+
22x()cos
hp40g+.book Page 43 Friday, December 9, 2005 1:03 AM
14-44 Computer Algebra System (CAS)
Typing:
TRIG(SIN(X)
2
+ COS(X)
2
+ 1)
gives:
2
TRIGCOS Simplify using the cosines
TRIGCOS has as an argument a trigonometric
expression.
TRIGCOS simplifies this expression, using the identity
sin(x)
2
+cos(x)
2
= 1 to rewrite it in terms of cosines.
Typing:
TRIGCOS(SIN(X)
4
+ COS(X)
2
+ 1)
gives:
TRIGSIN Simplify using the sines
TRIGSIN has as an argument a trigonometric expression.
TRIGSIN simplifies this expression, using the identity
sin(x)
2
+cos(x)
2
= 1 to rewrite it in terms of sines.
Typing:
TRIGSIN(SIN(X)
4
+ COS(X)
2
+ 1)
gives:
TRIGTAN Simplify using the tangents
TRIGTAN has as an argument a trigonometric expression.
TRIGTAN simplifies this expression, using the identity
sin(x)
2
+cos(x)
2
= 1 to rewrite it in terms of tangents.
Typing:
TRIGTAN(SIN(X)
4
+ COS(X)
2
+ 1)
gives:
x()
4
cos x()
2
cos 2+
x()
4
sin x()
2
sin 2+
2 x()
4
tan 3 x()
2
tan 2++
x()
4
tan 2+ x()
2
tan 1+
-------------------------------------------------------------------
hp40g+.book Page 44 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-45
CAS Functions on the MATH menu
When you are in the
Equation Writer and press
, a menu of
additional CAS functions
available to you is
displayed. Many of the
functions in this menu
match the functions available from the soft-key menus in
the Equation Writer; but there are other functions that are
only available from this menu. This section describes CAS
functions that are available when you press in the
Equation Writer (grouped by main menu name).
Algebra menu
All the functions on this menu are also available on the
menu in the Equation Writer. See “ALGB menu”
on page 14-10 for a description of these functions.
Complex menu
i Inserts i (= ).
ABS Determines the absolute value of the argument.
Example
Typing ABS(7 + 4i) yields , as does ABS(7 – 4i).
ARG See “ARG” on page 13-7.
CONJ See “CONJ” on page 13-7.
DROITE
DROITE returns the equation of the line through the
Cartesian points, z
1
, z
2
. It takes two complex numbers, z
1
and
z
2
, as arguments.
Example
Typing:
DROITE((1, 2), (0, 1))
or:
DROITE(1 + 2·i, i)
1
65
hp40g+.book Page 45 Friday, December 9, 2005 1:03 AM
14-46 Computer Algebra System (CAS)
returns:
Y = X –1 + 2
Pressing simplifies this to:
Y = X + 1
IM See “IM” on page 13-7.
Specifies the negation of the argument.
RE See “RE” on page 13-8.
SIGN
Determines the quotient of the argument divided by its
modulus.
Example
Typing SIGN(7 + 4i) or SIGN(7,4) yields .
Constant menu
e, i, π See “Constants” on page 13-8.
Enters the sign for infinity.
Diff & Int menu
All the functions on this menu are also available on the
menu in the Equation Writer. See “DIFF menu” on
page 14-16 for a description of these functions.
Hyperb menu
All the functions on this menu are described in
“Hyperbolic trigonometry” on page 13-9.
Integer menu
Note that many integer functions also work with Gaussian
integers (a + bi where a and b are integers).
74i+
65
--------------
hp40g+.book Page 46 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-47
DIVIS
Gives the divisors of an integer.
Example
Typing:
DIVIS(12)
gives:
12 OR 6 OR 3 OR 4 OR 2 OR 1
Note: DIVIS(0) returns 0 OR 1.
EULER
Returns the Euler index of a whole number. The Euler
index of n is the number of whole numbers less than n that
are prime with n.
Example
Typing:
EULER(21)
gives:
12
Explanation: {2,4,5,7,8,10,11,13,15,16,17,19} is
the set of whole numbers less than 21 and prime with 21.
There are 12 members of the set, so the Euler index is12.
FACTOR Decomposes an integer into its prime factors.
Example
Typing:
FACTOR(90)
gives:
2·3
2
·5
GCD
Returns the greatest common divisor of two integers.
Example
Typing:
GCD(18, 15)
gives:
3
hp40g+.book Page 47 Friday, December 9, 2005 1:03 AM
14-48 Computer Algebra System (CAS)
In step-by-step mode, there are a number of intermediate
results:
18 mod 15 = 3
15 mod 3 = 0
Result: 3
Pressing or then causes 3 to be written to the
Equation Writer.
Note that the last non-zero remainder in the sequence of
remainders shown in the intermediate steps is the GCD.
IDIV2
Returns the quotient and the remainder of the Euclidean
division between two integers.
Example
Typing:
IDIV2(148, 5)
gives:
29 AND 3
In step-by-step mode, the
calculator shows the
division process in
longhand.
IEGCD
Returns the value of Bézout’s Identity for two integers. For
example, IEGCD(A,B) returns U AND V = D, with U, V, D
such that AU+BV=D and D=GCD(A,B).
Example
Typing:
IEGCD(48, 30)
gives
2 AND –3 = 6
In other words: 2·48 + (–3)·30 = 6 and GCD(48,30) = 6.
In step-by-step mode, we get:
[z,u,v]:z=u*48+v*30
hp40g+.book Page 48 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-49
[48,1,0]
[30,0,1]*–1
[18,1,–1]*–1
[12,–1,2]*–1
[6,2,–3]*–2
Result: [6,2,–3]
Pressing or then causes 2 AND –3 = 6 to be
written to the Equation Writer.
The intermediate steps shown are the combination of
lines. For example, to get line L(n + 2), take L(n) – q*L(n
+ 1) where q is the Euclidean quotient of the integers at
the beginning of the vector, these integers being the
sequence of remainders).
IQUOT Returns the integer quotient of the Euclidean division of
two integers.
Example
Typing:
IQUOT(148, 5)
gives:
29
In step-by-step mode, the
division is carried out as if
in longhand
Pressing or
then causes 29 to be
written to the Equation
Writer.
IREMAINDER Returns the integer remainder from the Euclidean division
of two integers.
Example 1
Typing:
IREMAINDER(148, 5)
gives:
3
hp40g+.book Page 49 Friday, December 9, 2005 1:03 AM
14-50 Computer Algebra System (CAS)
IREMAINDER works with integers and with Gaussian
integers. This is what distinguishes it from MOD.
Example 2
Typing:
IREMAINDER(2 + 3·i, 1 + i)
gives:
i
ISPRIME? Returns a value indicating whether an integer is a prime
number. ISPRIME?(n) returns 1 (TRUE) if n is a prime or
pseudo-prime, and 0 (FALSE) if n is not prime.
Definition: For numbers less than 10
14
, pseudo-prime
and prime mean the same thing. For numbers greater
than 10
14
, a pseudo-prime is a number with a large
probability of being prime.
Example 1
Typing:
ISPRIME?(13)
gives:
1.
Example 2
Typing:
ISPRIME?(14)
gives:
0.
LCM Returns the least common multiple of two integers.
Example
Typing:
LCM(18, 15)
gives:
90
MOD See “MOD” on page 13-15.
hp40g+.book Page 50 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-51
NEXTPRIME NEXTPRIME(n) returns the smallest prime or pseudo-prime
greater than n.
Example
Typing:
NEXTPRIME(75)
gives:
79
PREVPRIME PREVPRIME(n) returns the greatest prime or pseudo-prime
less than n.
Example
Typing:
PREVPRIME(75)
gives:
73
Modular menu
All the examples of this section assume that p =13; that
is, you have entered MODSTO(13) or
STORE(13,MODULO), or have specified 13 for Modulo
in CAS MODES screen (as explained on page 15-16).
ADDTMOD Performs an addition in Z/pZ.
Example 1
Typing:
ADDTMOD(2, 18)
gives:
–6
ADDTMOD can also perform addition in Z/pZ[X].
Example 2
Typing:
ADDTMOD(11X + 5, 8X + 6)
gives:
6x 2
hp40g+.book Page 51 Friday, December 9, 2005 1:03 AM
14-52 Computer Algebra System (CAS)
DIVMOD Division in Z/pZ or Z/pZ[X].
Example 1
In Z/pZ, the arguments are two integers: A and B. When
B has an inverse in Z/pZ, the result is A/B simplified as
Z/pZ.
Typing:
DIVMOD(5, 3)
gives:
6
Example 2
In Z/pZ[X], the arguments are two polynomials: A[X] and
B[X]. The result is a rational fraction A[X]/B[X] simplified
as Z/pZ[X].
Typing:
DIVMOD(2X
2
+ 5, 5X
2
+ 2X –3)
gives:
EXPANDMOD Expand and simplify expressions in Z/pZ or Z/pZ[X].
Example 1
In Z/pZ, the argument is an integer expression.
Typing:
EXPANDMOD(2 · 3 + 5 · 4)
gives:
0
Example 2
In Z/pZ[X], the argument is a polynomial.
Typing:
EXPANDMOD((2X
2
+ 12)·(5X – 4))
gives:
4x 5+
3x 3+
---------------
3 x
3
5 x
2
–5x 4+()
hp40g+.book Page 52 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-53
FACTORMOD Factors a polynomial in Z/pZ[X], providing that p 97,
p is prime and the order of the multiple factors is less than
the modulo.
Example
Typing:
FACTORMOD((3X
3
– 5X
2
+ 5X – 4))
gives:
GCDMOD Calculates the GCD of the two polynomials in Z/pZ[X].
Example
Typing:
GCDMOD(2X
2
+ 5, 5X
2
+ 2X – 3)
gives:
INVMOD Calculates the inverse of an integer in Z/pZ.
Example
Typing:
INVMOD(5)
gives:
–5
since 5 · –5 = –25 = 1 (mod 13).
MODSTO Sets the value of the MODULO variable p.
Example
Typing:
MODSTO(11)
sets the value of p to 11.
3x 5()x
2
6+()()
6x 1()
hp40g+.book Page 53 Friday, December 9, 2005 1:03 AM
14-54 Computer Algebra System (CAS)
MULTMOD Performs a multiplication in Z/pZ or in Z/pZ[X].
Example 1
Typing:
MULTMOD(11, 8)
gives:
–3
Example 2
Typing:
MULTMOD(11X + 5, 8X + 6)
gives:
POWMOD Calculates A to the power of N in Z/pZ[X], and A(X) to
the power of N in Z/pZ[X].
Example 1
If p = 13, typing:
POWMOD(11, 195)
gives:
5
In effect: 11
12
= 1 mod 13, so 11
195
= 11
16×12+3
= 5
mod 13.
Example 2
Typing:
POWMOD(2X + 1, 5)
gives:
since 32 = 6 (mod 13), 80 = 2 (mod 13), 40 = 1 (mod
13), 10 = –3 (mod 13).
3x
2
2x–4()
6x
5
2x
4
2x
3
x
2
3x–1+++ +
hp40g+.book Page 54 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-55
SUBTMOD Performs a subtraction in Z/pZ or Z/pZ[X].
Example 1
Typing:
SUBTMOD(29, 8)
gives:
–5
Example 2
Typing:
SUBTMOD(11X + 5, 8X + 6)
gives:
Polynomial menu
EGCD Returns Bézout’s Identity, the Extended Greatest Common
Divisor (EGCD).
EGCD(A(X), B(X)) returns U(X) AND V(X) = D(X), with D,
U, V such that D(X) = U(X)·A(X) + V(X)·B(X).
Example 1
Typing:
EGCD(X
2
+ 2 · X + 1, X
2
– 1)
gives:
AND
Example 2
Typing:
EGCD(X
2
+ 2 · X + 1, X
3
+ 1)
gives:
AND
3x 1
1–1–2x 2+=
x 2()–13x 3+=
hp40g+.book Page 55 Friday, December 9, 2005 1:03 AM
14-56 Computer Algebra System (CAS)
FACTOR Factors a polynomial.
Example 1
Typing:
FACTOR(X
2
– 2)
gives:
Example 2
Typing:
FACTOR(X
2
+ 2·X + 1)
gives:
GCD Returns the GCD (Greatest Common Divisor) of two
polynomials.
Example
Typing:
GCD(X
2
+ 2·X + 1, X
2
– 1)
gives:
HERMITE Returns the Hermite polynomial of degree n (where n is a
whole number). This is a polynomial of the following type:
Example
Typing:
HERMITE(6)
gives:
x 2+()x 2()
x 1+()
2
x 1+
H
n
x() 1()
n
e
x
2
2
-----
d
n
dx
n
--------
e
x
2
2
-----
=
64x
6
480x
4
–720x
2
120+
hp40g+.book Page 56 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-57
LCM Returns the LCM (Least Common Multiple) of two
polynomials.
Example
Typing:
LCM(X
2
+ 2·X + 1, X
2
– 1)
gives:
LEGENDRE Returns the polynomial L
n
, a non-null solution of the
differential equation:
where n is a whole number.
Example
Typing:
LEGENDRE(4)
gives:
PARTFRAC Returns the partial fraction decomposition of a rational
fraction.
Example
Typing:
gives, in real and direct mode:
and gives, in complex mode:
x
2
2x 1++()x 1()
x
2
1()y 2 xy nn 1+()y⋅⋅ 0=
35 x
4
30 x
2
3+
8
----------------------------------------------
A
RTFRAC
X
5
2X
3
–1+
X
4
2X
3
–2X
2
2X–1++
----------------------------------------------------------
--
x 2
x 3
2x
2
2+
-----------------
1
2x 2
---------------
++ +
x 2
13i
4
------------------
xi+
------------------
1
2
------
x 1
-----------
13i+
4
------------------
xi
------------------
++ + +
hp40g+.book Page 57 Friday, December 9, 2005 1:03 AM
14-58 Computer Algebra System (CAS)
PROPFRAC PROPFRAC rewrites a rational fraction so as to bring out
its whole number part.
PROPFRAC(A(X)/ B(X)) writes the rational fraction A(X)/
B(X) in the form:
where R”(X) = 0, or 0 deg (R(X) < deg (B(X).
Example
Typing:
gives:
PTAYL PTAYL rewrites a polynomial P(X) in order of its powers of
X – a.
Example
Typing:
PTAYL(X
2
+ 2·X + 1, 2)
produces the polynomial Q(X), namely:
Note that P(X) = Q(X–2).
QUOT QUOT returns the quotient of two polynomials, A(X) and
B(X), divided in decreasing order by exponent.
Example
Typing:
QUOT(X
2
+ 2·X + 1, X)
gives:
Q
X()
RX()
BX()
------------
+
ROPFRAC
5X 3+()X 1()
X 2+
-------------------------------------------
5x 12
21
x 2+
------------
+
x
2
6x 9++
x 2+
hp40g+.book Page 58 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-59
Note that in step-by-step mode, synthetic division is
shown, with each polynomial represented as the list of its
coefficients in descending order of power.
REMAINDER Returns the remainder from the division of the two
polynomials, A(X) and B(X), divided in decreasing order
by exponent.
Example
Typing:
REMAINDER(X
3
– 1, X
2
– 1)
gives:
Note that in step-by-step mode, synthetic division is
shown, with each polynomial represented as the list of its
coefficients in descending order of power.
TCHEBYCHEFF For n > 0, TCHEBYCHEFF returns the polynomial T
n
such
that:
Tn(x) = cos(n·arccos(x))
For n 0, we have:
For n 0 we also have:
For n 1, we have:
If n < 0, TCHEBYCHEFF returns the 2nd-species
Tchebycheff polynomial:
x 1
T
n
x() C
2k
n
x
2
1()
k
x
n 2k
k 0=
n
2
---
[]
=
1 x
2
()T
n
x() xT
n
x() n
2
T
n
x()+0=
T
n 1+
x() 2xT
n
x() T
n 1
x()=
T
n
x()
n arccos x()()sin
arccos x()()sin
-------------------------------------------
=
hp40g+.book Page 59 Friday, December 9, 2005 1:03 AM
14-60 Computer Algebra System (CAS)
Example 1
Typing:
TCHEBYCHEFF(4)
gives:
Example 2
Typing:
TCHEBYCHEFF(–4)
gives:
Real menu
CEILING See “CEILING” on page 13-14.
FLOOR See “FLOOR” on page 13-14.
FRAC See “FRAC” on page 13-14.
INT See “INT” on page 13-15.
MAX See “MAX” on page 13-15.
MIN See “MIN” on page 13-15.
Rewrite menu
All the functions on this menu are also available on the
menu in the Equation Writer. See “REWRI menu”
on page 14-28 for a description of these functions.
Solve menu
All the functions on this menu are also available on the
menu in the Equation Writer. See “SOLV menu” on
page 14-33 for a description of these functions.
8x
4
8x
2
–1+
8x
3
4x
hp40g+.book Page 60 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-61
Tests menu
ASSUME Use this function to make a hypothesis about a specified
argument or variable.
Example
Typing:
ASSUME(X>Y)
sets an assumption that X is greater than Y. In fact, the
calculator works only with large not strict relations, and
thus ASSUME(X>Y) will actually set the assumption that X
Y. (A message will indicate this when you enter an
ASSUME function.) Note that X
Y will be stored in the
REALASSUME variable. To see the variable, press
, select REALASSUME and press .
UNASSUME Use this function to cancel all previously specified
assumptions about a particular argument or variable.
Example
Typing:
UNASSUME(X)
cancels any assumptions made about X. It returns X in the
Equation Writer. To see the assumptions, press ,
select REALASSUME and press .
>, , <, ≤, ==, See “Test functions” on page 13-19.
AND See “AND” on page 13-19.
OR See “OR” on page 13-19.
NOT See “NOT” on page 13-19.
IFTE See “IFTE” on page 13-19.
Trig menu
All the functions on this menu are also available on the
menu in the Equation Writer. See “TRIG menu” on
page 14-38 for a description of these functions.
hp40g+.book Page 61 Friday, December 9, 2005 1:03 AM
14-62 Computer Algebra System (CAS)
CAS Functions on the CMDS menu
When you are in the
Equation Writer and press
, a menu of
the full set of CAS functions
available to you is
displayed. Many of the
functions in this menu
match the functions available from the soft-key menus in
the Equation Writer; but there are other functions that are
only available from this menu. This section describes the
additional CAS functions that are available when you
press in the Equation Writer. (See the
previous section for other CAS commands.)
ABCUV This command applies the Bézout identity like EGCD, but
the arguments are three polynomials A, B and C. (C must
be a multiple of GCD(A,B).)
ABCUV(A[X], B[X], C[X]) returns U[X] AND V[X], where U
and V satisfy:
C[X] = U[X] · A[X] + V[X] · B[X]
Example 1
Typing:
ABCUV(X
2
+ 2 · X + 1, X
2
– 1, X + 1)
gives:
CHINREM Chinese Remainders: CHINREM has two sets of two
polynomials as arguments, each separated by AND.
CHINREM((A(X) AND R(X), B(X) AND Q(X)) returns an
AND with two polynomials as components: P(X) and S(X).
The polynomials P(X) and S(X) satisfy the following
relations when GCD(R(X),Q(X)) = 1:
S(X) = R(X) · Q(X),
P(X) = A(X) (modR(X)) and P(X) = B(X) (modQ(X)).
There is always a solution, P(X), if R(X) and Q(X) are
mutually primes and all solutions are congruent modulo
S(X) = R(X) · Q(X).
1
2
-
--
AND
1
2
-
--
hp40g+.book Page 62 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-63
Example
Find the solutions P(X) of:
P(X) = X (mod X
2
+ 1)
P(X) = X – 1 (mod X
2
– 1)
Typing:
CHINREM((X) AND (X
2
+ 1), (X – 1) AND (X
2
– 1))
gives:
That is:
CYCLOTOMIC Returns the cyclotomic polynomial of order n. This is a
polynomial having the nth primitive roots of unity as
zeros.
CYCLOTOMIC has an integer n as its argument.
Example 1
When n = 4 the fourth roots of unity are {1, i, –1, –i}.
Among them, the primitive roots are: {i, –i}. Therefore, the
cyclotomic polynomial of order 4 is (X – i).(X + i) = X
2
+ 1.
Example 2
Typing:
CYCLOTOMIC(20)
gives:
EXP2HYP EXP2HYP has an expression enclosing exponentials as an
argument. It transforms that expression with the relation:
exp(a) = sinh(a) + cosh(a).
x
2
2x–1+
2
--------------------------
AND
x
4
1
2
--------------
P
X[]
x
2
2x–1+
2
--------------------------
mod
x
4
1
2
--------------
=
x
8
x
6
x
4
x
2
–1++
hp40g+.book Page 63 Friday, December 9, 2005 1:03 AM
14-64 Computer Algebra System (CAS)
Example 1
Typing:
EXP2HYP(EXP(A))
gives:
sinh(a) + cosh(a)
Example 2
Typing:
EXP2HYP(EXP(–A) + EXP(A))
gives:
2 · cosh(a)
GAMMA Returns the values of the Γ function at a given point.
The Γ function is defined as:
We have:
Γ (1) = 1
Γ (x + 1) = x · Γ (x)
Example 1
Typing:
GAMMA(5)
gives:
24
Example 2
Typing:
GAMMA(1/2)
gives:
IABCUV IABCUV(A,B,C) returns U AND V such that AU + BV = C
where A, B and C are whole numbers.
C must be a multiple of GCD(A,B) to obtain a solution.
Γ x() e
t
t
x 1
td
0
+
=
π
hp40g+.book Page 64 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-65
Example
Typing:
IABCUV(48, 30, 18)
gives:
6 AND –9
IBERNOULLI Returns the nth Bernoulli’s number B(n) where:
Example
Typing:
IBERNOULLI(6)
gives:
ICHINREM Chinese Remainders: ICHINREM(A AND P,B AND Q)
returns C AND R, where A, B, P and Q are whole
numbers.
The numbers X = C + k · R where k is an integer are such
that X = A mod P and X = B mod Q.
A solution X always exists when P and Q are mutually
prime, (GCD(P,Q) = 1) and in this case, all the solutions
are congruent modulo R = P · Q.
Example
Typing:
ICHINREM(7 AND 10, 12 AND 15)
gives:
–3 AND 30
ILAP LAP is the Laplace transform of a given expression. The
expression is the value of a function of the variable stored
in VX.
t
e
t
1
-------------
Bn()
n!
-----------
t
n
n
0=
+
=
1
42
-----------
hp40g+.book Page 65 Friday, December 9, 2005 1:03 AM
14-66 Computer Algebra System (CAS)
ILAP is the inverse Laplace transform of a given
expression. Again, the expression is the value of a
function of the variable stored in VX.
Laplace transform (LAP) and inverse Laplace transform
(ILAP) are useful in solving linear differential equations
with constant coefficients, for example:
The following relations hold:
where c is a closed contour enclosing the poles of f.
The following property is used:
The solution, y, of:
is then:
Example
To solve:
c
type:
LAP(X · EXP(3 · X))
The result is:
y py qy++ fx()=
y 0() a y 0() b==
LAP(y)(x) e
x t
yt()td
0
+
=
ILAP(f)(x)
1
2iπ
--------
e
zx
fz()zd
c
=
L
AP y()x() y 0() x LAP y()x()+=
y py qy++ fx(), y 0() a, y 0() b===
ILAP
LAP fx()()xp+()ab++
x
2
px q++
-------------------------------------------------------------------
⎝⎠
⎛⎞
y 6 y 9 y+ xe
3x
, y 0() a, y 0() b===
1
x
2
6x–9+
--------------------------
hp40g+.book Page 66 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-67
Typing:
gives:
LAP See ILAP above.
PA2B2 Decomposes a prime integer p congruent to 1 modulo 4,
as follows:
p = a
2
+ b
2
.
The calculator gives the result as a + b · i.
Example 1
Typing:
PA2B2(17)
gives:
4 + i
that is, 17 = 4
2
+ 1
2
Example 2
Typing:
PA2B2(29)
gives:
5 + 2 · i
that is, 29 = 5
2
+ 2
2
PSI Returns the value of the nth derivative of the Digamma
function at a.
The Digamma function is the derivative of ln(Γ(x)).
Example
Typing:
PSI(3, 1)
I
LAP
1
X
2
6X–9+
----------------------------
X 6()ab++
X
2
6X–9+
-------------------------------------------------------------------
x
3
6
-----
3ab() xa+
⎝⎠
⎛⎞
e
3x
hp40g+.book Page 67 Friday, December 9, 2005 1:03 AM
14-68 Computer Algebra System (CAS)
gives:
Psi Returns the value of the Digamma function at a.
The Digamma function is defined as the derivative of
ln(Γ(x)), so we have PSI(a,0) = Psi(a).
Example
Typing:
Psi(3)
and pressing
gives:
.922784335098
REORDER Reorders the input expression following the order of
variables given in the second argument.
Example
Typing:
REORDER(X
2
+ 2 · X · A + A
2
+ Z
2
– X · Z, A AND X
AND Z)
gives:
SEVAL SEVAL simplifies the given expression, operating on all
but the top-level operator of the expression.
Example
Typing:
SEVAL(SIN(3 · X -– X) + SIN(X + X))
gives:
SIGMA Returns the discrete antiderivative of the input function,
that is, the function G, that satisfies the relation G(x + 1)
– G(x) = f(x). It has two arguments: the first is a function
f(x) of a variable x given as the second argument.
5
4
---
1
6
---
π
2
+
A
2
2+ XA⋅⋅ X
2
Z+ XZ
2
+
2 x()sin 2 x()sin+
hp40g+.book Page 68 Friday, December 9, 2005 1:03 AM
Computer Algebra System (CAS) 14-69
Example
Typing:
SIGMA(X · X!, X)
gives:
X!
because (X + 1)! – X! = X · X!.
SIGMAVX Returns the discrete antiderivative of the input function,
that is a function, G, that satisfies the relation: G(x + 1) –
G(x) = f(x). SIGMAVX has as its argument a function f of
the current variable VX.
Example
Typing:
SIGMAVX(X
2
)
gives:
because:
STURMAB Returns the number of zeros of P in [a, b[ where P is a
polynomial and a and b are numbers.
Example 1
Typing:
STURMAB(X
2
· (X
3
+ 2), –2, 0)
gives:
1
Example 2
Typing:
STURMAB(X
2
· (X
3
+ 2), –2, 1)
gives:
3
2x
3
3x
2
x+
6
--------------------------------
2 x 1+()
3
3 x 1+()
2
x 12x
3
–3x
2
x++ + 6x
2
=
hp40g+.book Page 69 Friday, December 9, 2005 1:03 AM
14-70 Computer Algebra System (CAS)
TSIMP Simplifies a given expression by rewriting it as a function
of complex exponentials, and then reducing the number
of variables (enabling complex mode in the process).
Example
Typing:
gives:
VER Returns the version number of your CAS.
Example
Typing:
VER
might give:
4.20050219
This particular result means that you have a version 4
CAS, dated 19 February 2005. Note that this is not the
same as VERSION (which returns the version of the
calculator’s ROM).
T
SIMP
SIN 3X()SIN 7X()+
SIN 5X()
---------------------------------------------------
EXP ix()
4
1+
EXP ix()
2
--------------------------------------
hp40g+.book Page 70 Friday, December 9, 2005 1:03 AM
Equation Writer 15-1
15
Equation Writer
Using CAS in the Equation Writer
The Equation Writer enables you to type expressions that
you want to simplify, factor, differentiate, integrate, and
so on, and then work them through as if on paper.
The key on the HOME
screen menu bar opens the
Equation Writer, and the
key closes it.
This chapter explains how to
write an expression in the Equation Writer using the
menus and the keyboard, how to select a subexpression,
how to apply CAS functions to an expression or
subexpression and how to store values in the Equation
Writer variables.
Chapter 14 explains all the symbolic calculation functions
contained in the various menus, and chapter 16 provides
numerous examples showing the use of the Equation
Writer.
The Equation Writer menu bar
The Equation Writer has a
number of soft menu keys.
TOOL menu Unlike the other soft menu
keys, the menu does
not give access to CAS
commands. Instead, it
provides access to a number
of utilities to help you work
with the Equation Writer. The following table explains
each of the utilities on the menu.
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
15-2 Equation Writer
ALGB menu The menu contains
functions that enable you to
perform algebra, such as
factoring, expansion,
simplification, substitution,
and so on.
DIFF menu The menu contains
functions that enable you to
perform differential calculus,
such as differentiation,
integration, series
expansion, limits, and so on.
Cursor mode Enables you to go into cursor
mode, for quicker selection of
expressions and
subexpressions (see
page 15-10).
Edit expr. Enables you to edit the
highlighted expression on the
edit line, just as you do in the
HOME screen (see
page 15-11).
Change font Enables you to choose to type
using large or small
characters (see page 15-10).
Cut Copies the selection to the
clipboard and erases the
selection from Equation
Writer.
Copy Copies the selection to the
clipboard.
Paste Copies the contents of the
clipboard to the location of
the cursor. The clipboard
contents will be either
whatever Copy or Cut
selected the last time you
used these commands, or the
highlighted level when you
selected COPY in CAS
history.
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Equation Writer 15-3
REWRI menu The menu contains
functions that enable you to
rewrite an expression in
another form.
SOLV menu The menu contains
functions that enable you to
solve equations, linear
systems, and differential
equations.
TRIG menu The menu contains
functions that enable you to
transform trigonometric
expressions.
NOTE
You can get online help about any CAS function by
pressing 2 and selecting that function (as
explained in “Online Help” on page 14-8).
Configuration menus
You can directly see, and change, CAS modes while
working with the Equation Writer. The first line in each of
the Equation Writer menus (except ) indicates the
current CAS mode settings.
In the example at the right,
the first line of the
menu reads:
CFG R= X S
CFG stands for
“configuration”, and the symbols to the right of it indicate
various mode settings.
The first symbol, R, indicates that you are in real
mode. If you were in complex mode, this symbol
would be C.
The second symbol, =, indicates that you are in exact
mode. If you were in approximate mode, this symbol
would be ~.
The third symbol, X in the above example, indicates
the current independent variable.
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
15-4 Equation Writer
The fourth symbol, S, in the above example, indicates
that you are in step-by-step mode. If you were not in
step-by-step mode, this symbol would be D (which
stands for Direct).
The first line of an Equation
Writer menu only indicates
some of the mode settings.
To see more settings,
highlight the first line and
press . The configuration
menu appears. The header of the configuration menu has
additional symbols. In the example above, the upward-
pointing arrow indicates that polynomials are displayed
with increasing powers, and the 13 indicates the modulo
value.
You can change CAS mode settings directly from the
configuration menu. Just press until the setting you
want to choose is highlighted and then press .
Note that the configuration menu includes only those
options that are not currently selected. For example, if
Rigorous is a current setting, its opposite, Sloppy, will
appear on the menu. If you choose Sloppy, then
Rigorous appears in its place.
To return your CAS modes to their default settings, select
Default cfg and press .
To close the configuration menu, select Quit config
and press .
NOTE
You can also change CAS mode settings from CAS
MODES screen. See “CAS modes” on page 14-5 for
information.
Online Help
language
One CAS setting that only
appears on the configuration
menu is the setting that
determines the language of
the online help. Two
languages are available:
English and French. To choose French, select Francais
and press . To return to English, select English and
press .
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Equation Writer 15-5
Entering expressions and subexpressions
You type expressions in the Equation Writer is much the
same way as you type them in the HOME screen, using
the keys to directly enter numbers, letters and operators,
and menus to select various functions and commands.
When you type an expression in the Equation Writer, the
operator that you are typing always carries over to the
adjacent or selected expression. You don’t have to worry
about where the parentheses go: they are automatically
entered for you.
It will help you understand how the Equation Writer works
if you view a mathematical expression as a tree, with the
four arrow keys enabling you to move through the tree:
the and keys enable you to move from one
branch to another
the and keys enable you to move up and
down a particular tree
the and key combinations
enable you to make multiple selections.
How do I select? There are two ways of going into selection mode:
Pressing takes you into selection mode and
selects the element adjacent to the cursor. For
example:
1+2+3+4
selects 4. Pressing it again selects the entire tree:
1+2+3+4.
Pressing takes you into selection mode and
selects the branch adjacent to the cursor. Pressing it
augments the selection, adding the next branch to the
right. For example:
1+2+3+4
selects 3+4. Pressing it again selects 2+3+4, and again
selects 1+2+3+4.
NOTE:
If you are typing a templated function with multiple
arguments (such as , ,SUBST, etc.), pressing or
enables you to move from one argument to another. In
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
15-6 Equation Writer
this case, you have to press to select elements in the
expression.
The following illustration shows how an expression can
be viewed as a tree in the Equation Writer. It illustrates a
tree view of the expression:
Suppose that the cursor is positioned to the right of 3:
If you press once, the 3 component is selected.
If you press again, the selection moves up the
tree, with x + 3 now selected.
If you press again, the selection moves up the
tree, and now the entire expression is selected.
If you had pressed instead of when the
cursor was positioned to the right of 3, the leaves of
the branch get selected (that is, x + 3).
If you press again, the selection moves up the
tree, and now the entire expression is selected.
If you now press , just the numerator is selected.
If you now press again, the top-most branch
selected (that is, (5x + 3).
Continue pressing to select each top-most leaf in
turn (5x and then 5).
5x 3+()x 1()
x 3+
-----------------------------------------
÷
×
+
×
+
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
Equation Writer 15-7
Press again and again to progressively select
more of the top-most branch, and then lower
branches (5x, 5x + 3, and then the entire numerator
and finally the entire expression).
More Examples Example1
If you enter:
2 + X × 3– X
and press the
entire expression is selected.
Pressing evaluates
what is selected (that is, the
entire expression) and
returns:
2X + 2
If you enter the same expression as earlier but press
after the first X, as in:
2 + X × 3 – X
the 2 + X is selected and the
next operation,
multiplication, is applied to
to it. The expression
becomes:
(2 + X) × 3 – X
Pressing selects the
entire expression, and
pressing evaluates it,
resulting in:
2X + 6
Now enter the same expression, but press after the
3, as in:
2 + X × 3 – X
Note that selects the
expression so far entered (2
+ X) thus making the next
operation apply to the entire
selection, not just the last
entered term. The key
selects just the last entry (3) and makes the next operation
hp40g+.book Page 7 Friday, December 9, 2005 1:03 AM
15-8 Equation Writer
(– X) apply to it. As a result, the entered expression is
interpreted, and displayed, as (2 + X)(3 – X).
Select the entire expression
by pressing and
evaluate it by pressing
. The result is:
–(X
2
–X–6)
Example2
To enter X
2
–3X+1, press:
2 – 3
+1
If, instead, you had to enter
–x
2
–3X+1, you would need
to press:
(–) 2 – 3 +1
Note that you press twice to ensure that the exponent
applies to –X and not just to X.
Example 3
Suppose you want to enter:
Each fraction can be viewed
as a separate branch on the
equation tree. In the
Equation Writer type the first
branch:
1 ÷ 2
and then select this branch by pressing .
Now type + and enter the second branch:
1 ÷ 3
Select the second branch by pressing .
Now type + and enter the third branch:
1 ÷ 4
Likewise, select the third branch by pressing , type +
and then the fourth branch:
1 ÷ 5
1
2
---
1
3
---
1
4
---
1
5
---
+++
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
Equation Writer 15-9
Select the fifth branch by
pressing . At this point,
the desired expression is in
the Equation Writer, as
shown at the right.
Suppose that you want to select the second and third
branches, that is: . First press . This selects ,
the second term.
Now press . This
key combination enables
you to select two contiguous
branches, the one already
selected and the one to the
right of it.
If you want, you can
evaluate the selected part by
pressing . The result
is shown at the right.
Suppose now you want to
perform the partial calculation:
Because the two terms in this partial calculation are not
contiguous (that is, side by side), you must first perform a
permutation so that they are side by side.To do this,
press:
This exchanges the selected
element with its neighbour to
the left. The result is shown at
the right.
Now press:
to select just the branches
you are interested in:
1
3
---
1
4
---
+
1
3
---
1
2
---
1
5
---
+
hp40g+.book Page 9 Friday, December 9, 2005 1:03 AM
15-10 Equation Writer
Pressing produces
the result of the partial
calculation.
Summing up
Pressing enables you to select the current
element and its neighbour to the right. enables
you to exchange the selected element with its neighbour
to the left. The selected element remains selected after you
move it.
Cursor mode In cursor mode you can select a large expression quickly.
To select cursor mode, press:
Cursor mode
As you press the arrow key,
various parts of the
expression are enclosed n in
a box.
When what you want to
select is enclosed, press
to select it.
Changing the
font
If you are entering a long expression, you may find it
useful to reduce the size of the font used in the Equation
Writer. Select Change font from the menu. This
enables you to view a large expression in its entirety
when you need to. Selecting Change font again
returns the font size to its previous setting.
You can also see the selected expression or
subexpression is a smaller or larger font size by pressing
and then (to use the smaller font) or
(to use the larger font).
hp40g+.book Page 10 Friday, December 9, 2005 1:03 AM
Equation Writer 15-11
How to modify an expression
If you’re typing an expression, the key enables you
to erase what you’ve typed. If you’re selecting, you can:
Cancel the selection without deleting the expression
by pressing . The cursor moves to the end of the
deselected portion.
Replace the selection with an expression, just by
typing the desired expression.
Transform the selected expression by applying a CAS
function to it (which you can invoke from one of CAS
menus along the bottom of the screen).
Delete the selected expression by pressing:
Delete a selected unary operator at the top of the
expression tree by pressing:
For example, to replace SIN(expr) with COS(expr),
select SIN(expr), press and then press
COS.
Delete a binary infix operator and one of its
arguments by selecting the argument you want delete
and pressing:
For example, if you have the expression 1+2 and
select 1, pressing deletes 1+ and leaves
only 2. Similarly, to delete F(x)= in the expression F(x)
= x
2
x +1, you select F(x) and then press
. This produces x = x
2
x +1.
Delete a binary operator by selecting:
Edit expr.
from the menu and then making the correction.
Copy an element from CAS history. You access CAS
history by pressing . See page 15-19 for
details.
hp40g+.book Page 11 Friday, December 9, 2005 1:03 AM
15-12 Equation Writer
Accessing CAS functions
While you are in the Equation Writer, you can access all
CAS functions, and you can access them in various ways.
General principle: When you have written an
expression in the Equation Writer, all you have to do is
press to evaluate whatever you have selected (or
the entire expression, if nothing is selected).
How to type
Σ and
Press to enter Σ and to enter .
These symbols and are treated as prefix functions with
multiple arguments. They are automatically placed before
the selected element, if there is one (hence the term prefix
functions).
You can move the cursor from argument to argument by
pressing or .
Enter the expressions according to the rules of selection
explained earlier, but you must first go into selection
mode by pressing .
NOTE
Do not use the index i to define a summation, because i
designates the complex-number solution of x
2
+ 1 = 0.
Σ performs exact calculations if its argument has a
discrete primitive; otherwise it performs approximate
calculations, even in exact mode. For example, in both
approximate and exact mode:
= 2.70833333334
whereas in exact mode:
Note that
Σ can symbolically calculate summations of
rational fractions and hypergeometric series that allow a
discrete primitive. For example, if you type:
1
k!
----
k 0=
4
1
1
1!
-----
1
2!
-----
1
3!
-----
1
4!
-----
++++
65
24
------
=
1
KK1+()
--------------------------
K
1=
4
hp40g+.book Page 12 Friday, December 9, 2005 1:03 AM
Equation Writer 15-13
select the entire expression and press , you
obtain:
However, if you type:
select the entire expression and press , you
obtain 1.
How to enter infix
functions
An infix function is one that is typed between its
arguments. For example, AND, |and MOD are infix
functions.You can either:
type them in Alpha mode and then enter their
arguments, or
select them from a CAS menu or by pressing an
appropriate key, provided that you have already
written and selected the first argument.
You move from one argument to the other by pressing
and . The comma enables you to write a
complex number: when you type (1,2), the
parentheses are automatically placed when you type
the comma. If you want to type (–1,2), you must
select –1 before you type the comma.
How to enter prefix
functions
A prefix function is one that is typed before its arguments.
To enter a prefix function, you can:
type the first argument, select it, then select the
function from a menu, or
you can select the function from a menu, or by
directly entering it in Alpha mode, and then type the
arguments.
The following example illustrates the various ways of
entering a prefix function. Suppose you want to factor the
expression x
2
4, then find its value for x = 4. FACTOR is
the function for factoring, and it is found on the
menu. SUBST is the function for substituting a value for a
variable in an expression, and it is also found in the
menu.
l
4
5
---
1
KK1+()
--------------------------
K
1=
hp40g+.book Page 13 Friday, December 9, 2005 1:03 AM
15-14 Equation Writer
First option: function first, then arguments
In the Equation Writer, press
, select FACTOR and
then press or .
FACTOR() is displayed in
the Equation Writer, with the
cursor between the
parentheses (as shown at the right).
Enter your expression, using
the rules of selection
described earlier.
2 4
The entire expression is now selected.
Press then produce
the result.
With a blank Equation
Writer screen, press ,
select SUBST and then press
or .
With the cursor between the
parentheses at the location of the first argument, type your
expression.
Note that SUBST has two
arguments. When you have
finished entering the first
argument (the expression),
press to move to the
second argument.
Now enter the second
argument, x=4.
hp40g+.book Page 14 Friday, December 9, 2005 1:03 AM
Equation Writer 15-15
Press to obtain the an
intermediate result (4
2
– 4)
and again to
evaluate the intermediate
result. The final answer is 12.
Second option: arguments first, then function
Enter your expression, using
the rules of selection
described earlier.
2 4
The entire expression is now selected.
Now press and select
FACTOR. Notice that the
FACTOR is applied to
whatever was selected
(which is automatically
placed in parentheses).
Press to evaluate the
expression. The result is the
factors of the expression.
Because the result of an
evaluation is always
selected, you can immediately apply another command
to it.
To illustrate this, press
, select SUBST and
then press or .
Note that SUBST is applied
to whatever was selected
(which is automatically
placed in parentheses). Note too that the cursor is
automatically placed in the position of the second
argument.
Enter the second argument,
x=4.
hp40g+.book Page 15 Friday, December 9, 2005 1:03 AM
15-16 Equation Writer
Press to obtain an
intermediate result, (4– 2)(4
+ 2), and again to
evaluate the intermediate
result. The final answer, as
before, is 12.
Note
If you call a CAS function while you’re writing an
expression, whatever is currently selected is copied to the
function’s first or main argument. If nothing is selected,
the cursor is placed at the appropriate location for
completing the arguments.
Equation Writer variables
You can store objects in variables, then access an object
by using the name of its variable. However, you should
note the following:
Variables used in CAS cannot be used in HOME, and
vice versa.
In HOME or in the program editor, use to store
an object in a variable.
In CAS, use the STORE command (on the
menu) to store a value in a variable.
The key displays a menu that contains all the
available variables. Pressing while you are in
HOME displays the names of the variables defined in
HOME and in the Aplets. Pressing while you
are in the Equation Writer displays the names of the
variables defined in CAS (as explained on
page 15-18).
Predefined CAS variables
VX contains the name of the current symbolic
variable. Generally, this is X, so you should not use X
as the name of a numeric variable. Nor should you
erase the contents of X with the UNASSIGN command
(on the menu) after having done a symbolic
calculation.
EPS contains the value of epsilon used in the EPSX0
command.
hp40g+.book Page 16 Friday, December 9, 2005 1:03 AM
Equation Writer 15-17
MODULO contains the value of p for performing
symbolic calculations in Z/pZ or in Z/pZ[X]. You can
change the value of p either with the MODSTO
command on the MODULAR menu, (by typing, for
example, MODSTO(n) to give p a value of n), or from
CAS MODES screen (see page 14-5).
PERIOD must contain the period of a function before
you can find its Fourier coefficients.
PRIMIT contains the primitive of the last integrated
function.
REALASSUME contains a list of the names of the
symbolic variables that are considered reals. If you’ve
chosen the Cmplx vars option on the CFG
configuration menu, the defaults are X, Y, t, S1 and
S2, as well as any integration variables that are in
use.
If you’ve chosen the Real vars option on the CFG
configuration menu, all symbolic variables are
considered reals. You can also use an assumption to
define a variable such as X >1. In a case like this,
you use the ASSUME(X>1) command to make
REALASSUME contain X>1. The command
UNASSUME(X) cancels all the assumptions you have
previously made about X.
To see these variables, as well as those that you’ve
defined in CAS, press in the Equation Editor
(see “CAS variables” on page 14-4).
The keyboard in the Equation Writer
The keys mentioned in this section have different functions
when pressed in the Equation Writer than when used
elsewhere.
MATH key The key, if pressed in
the Equation Writer, displays
just those functions used in
symbolic calculation. These
functions are contained in
the following menus:
The five function-containing Equation Writer menus
outlined in the previous section: Algebra (),
hp40g+.book Page 17 Friday, December 9, 2005 1:03 AM
15-18 Equation Writer
Diff&Int (), Rewrite (), Solve
() and Trig ().
The Complex menu, providing functions specific to
manipulating with complex numbers.
The Constant menu, containing e, i,and π.
The Hyperb. menu, containing hyperbolic functions.
The Integer menu, containing functions that enable
you to perform integer arithmetic.
The Modular menu, containing functions that enable
you to perform modular arithmetic (using the value
contained in the MODULO variable).
The Polynom.menu, containing functions that enable
you to perform calculations with polynomials.
The Real menu, containing functions specific to
common real-number calculations
The Tests menu, containing logic functions for
working with hypotheses.
SHIFT MATH keys The key
combination opens an
alphabetical menu of all
CAS commands. You can
enter a command by
selecting it from this menu, so
that you don’t have to type it in ALPHA mode.
VARS key Pressing while you’re
in the Equation Writer
displays the names of the
variables defined in CAS.
Take special note of namVX,
which contains the name of
the current variable.
The menu options on the variables screen are:
Press to copy the name of the highlighted variable
to the position of the cursor in Equation Writer.
Press to see the contents of the highlighted
variable.
Press to change the contents of the highlighted
variable.
hp40g+.book Page 18 Friday, December 9, 2005 1:03 AM
Equation Writer 15-19
Press to clear the value of the highlighted variable.
Press to change the name of the highlighted
variable.
Press to define a new variable (which you do by
specifying an object and a name for the object.
SYMB key Pressing the key in
the Equation Writer gives
you access to CAS history.
As in the HOME screen
history, the calculations are
written on the left and the
results are written on the right. Using the arrow keys, you
can scroll through the history.
Press to copy the highlighted entry in history to the
clipboard in order to paste it in the Equation Writer. Press
or to replace the current selection in
Equation Writer with the highlighted entry in CAS history.
Press to leave CAS history without changing it in
any way.
SHIFT SYMB or
SHIFT HOME keys
While you are working in the
Equation Writer, pressing
or
opens CAS MODES
screen. The various CAS
modes are described in
“CAS modes” on page 14-5.
SHIFT , key Pressing followed by the comma key undoes (that
is, cancels) your last operation.
PLOT key Pressing in the
Equation Writer displays a
menu of plot types. You can
choose to graph a function,
a parametric curve, or a
polar curve.
Depending on what you
choose, the highlighted
expression is copied into the
appropriate aplet, to the
destination that you specify.
hp40g+.book Page 19 Friday, December 9, 2005 1:03 AM
15-20 Equation Writer
NOTE
This operation supposes that the current variable is also
the variable of the function or curve you want to graph.
When the expression is copied, it is evaluated, and the
current variable (contained in VX) is changed to X, T, or
θ, depending on the type of plot you chose.
If the function depends on a parameter, it is preferable to
give the parameter a value before pressing . If,
however, you want the parameterized expression to be
copied with its parameter, then the name of the
parameter must consist of a single letter other than X, T,
or θ, so that there is no confusion. If the highlighted
expression has real values, the Function, Aplet or Polar
Aplet can be chosen, and the graph will be of Function or
Polar type. If the highlighted expression has complex
values, the Parametric Aplet must be chosen, and the
graph will be of Parametric type.
To summarize. If you choose:
the Function Aplet, the highlighted expression is
copied into the chosen function Fi, and the current
variable is changed to X.
the Parametric Aplet, the real part and the imaginary
part of the highlighted expression are copied into the
chosen functions Xi,Yi, and the current variable is
changed to T.
the Polar Aplet, the highlighted expression is copied
into the chosen function Ri and the current variable is
changed to θ.
NUM key Pressing in the Equation Writer causes the
highlighted expression to be replaced by a numeric
approximation. puts the calculator into
approximate mode.
SHIFT NUM key Pressing in the Equation Writer causes the
highlighted expression to be replaced by a rational
number. puts the calculator into exact
mode.
VIEWS key Pressing in the Equation Writer enables you to
move the cursor with the and arrow keys to see
the entire highlighted expression. Press to return in
the Equation Writer.
hp40g+.book Page 20 Friday, December 9, 2005 1:03 AM
Equation Writer 15-21
Short-cut keys In the Equation Writer, the following are short-cut keys to
the symbols indicated:
0 for
1 for i
3 for π
5 for <
6 for >
8 for
9 for
hp40g+.book Page 21 Friday, December 9, 2005 1:03 AM
hp40g+.book Page 22 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-1
16
Step-by-Step Examples
Introduction
This chapter illustrates the power of CAS, and the
Equation Writer, by working though a number of
examples. Some of these examples are variations on
questions from senior math examination papers.
The examples are given in order of increasing difficulty.
Example 1 If A is:
calculate the result of A in the form of an irreducible
fraction, showing each step of the calculation.
Solution: In the Equation
Writer, enter A by typing:
3 2 1
1 2
1
Now press to select the denominator (as shown
above).
Press to simplify the
denominator.
Now select the numerator
by pressing .
3
2
---
1
1
2
---
1+
------------
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
16-2 Step-by-Step Examples
Press to simplify the
numerator.
Press to select the
entire fraction.
Press to simplify the
selected fraction, giving
the result shown at the
right.
Example 2 Given that
write C in the form , where d is a whole number.
Solution: In the Equation Writer, enter C by typing:
2 45
3
12
20 6
3
Press to
select .
Press to select
and to
select 20.
Now press ,
select FACTOR and
press .
C 2 45 3 12 20–63+=
d 5
63
20
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-3
Press to factor
20 into .
Press to select
and to
simplify it.
Press to select
and
to exchange with
.
Press to select
and
to select 45.
Press , select
FACTOR and press
.
Press to factor
45 into .
Press to select
and to
simplify the selection.
Press to select
, and
to select
.
2
2
5
2
2
5
25
312
25
245
3
2
5
3
2
5
235
235 25
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
16-4 Step-by-Step Examples
Press to
evaluate the selection.
It remains to transform
and combine it
with . Follow the
same procedure as
undertaken a number of
times above. You will find that is equal to
, and so the final two terms cancel each other
out.
Hence the result is
Example 3 Given the expression :
expand and reduce D
factor D
solve the equation and
evaluate D for x = 5.
Solution: First, enter D using the Equation Writer:
3 X 1
2 81
Press to select
and to
expand the expression. This
gives:
312
63
312
63
C 45=
D 3x 1()
2
81=
3x 10()3x 8+() 0=
3X 1()
2
9x
2
6x–181+
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-5
Press to select the entire
equation, then press
to reduce it to
.
Press , select
FACTOR, press and
then . The result is
as shown at the right.
Now press , select
SOLVEVX, press and
press . The result is
shown at the right.
Press to display
CAS history, select D or a
version of it, and press .
Press , select SUBST,
press and, then
complete the second
argument:
Press to select
the entire expression and
then to obtain the
intermediate result shown.
Press once more to
yield the result: .
Therefore, when
.
Example 4 A baker produces two assortments of biscuits and
macaroons. A packet of the first assortment contains 17
biscuits and 20 macaroons. A packet of the second
assortment contains 10 biscuits and 25 macaroons. Both
packets cost 90 cents.
Calculate the price of one biscuit, and the price of one
macaroon.
Solution: Let x be the price of one biscuit, and y the
price of one macaroon. The problem is to solve:
9x
2
6x–80
x 5=
175
D 175=
x 5=
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
16-6 Step-by-Step Examples
Press , select
LINSOLVE and press .
Enter 17 X 20
Y 90
10
X 25 Y
90 X
Y
If you are working in step
by step mode, pressing
produces the result
at the right.
Press again to
produce the next step in the
solution:
Press again to
produce the reduction
result:
Pressing again
produces the final result:
If you select , and press
you get X = 2 and Y
= 2.8. In other words, the
price of one biscuit is 2
cents, and the price of one
macaroon is 2.8 cents.
Exercise 5 Suppose that A and B are points having the coordinates
(–1, 3) and (–3,–1) respectively, and where the unit of
measure is the centimetre.
17x 20y 90=+
10x 25y 90=+
14
5
------
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-7
1. Find the exact length of AB in centimetres.
2. Determine the equation of the line AB.
First method Type:
STORE((-1,3),A)
and press .
Accept the change to
Complex mode, if
necessary.
Note that pressing
returns the coordinates in
complex form: –1+3i.
Now type:
STORE((-3,-1),B)
and press .
The coordinates this time are represented as –3+–1·i.
The vector AB has coordinates B – A.
Type:
(B - A)
Press . The result is
.
Now apply the DROITE
command to determine the
equation of the line AB:
Complex
DROITE A
B
Pressing gives an
intermediate result.
25
hp40g+.book Page 7 Friday, December 9, 2005 1:03 AM
16-8 Step-by-Step Examples
Press again to
simplify the result to
Y = 2X+5.
Second method Type:
(-3,-1 )-(-1,3)
The answer is –(2+4i).
With the answer still
selected, apply the ABS
command by pressing
.
Pressing gives , the same answer as with
method 1 above.
You can also determi1ne the equation of the line by
typing:
DROITE(( -1,3), (-3,-1))
Pressing then gives the result obtained before:
Y = –(2X+5).
Exercise 6 In this exercise, we consider some examples of integer
arithmetic.
Part 1
For n, a strictly positive integer, we define:
1. Compute a
1
, b
1
, c
1
, a
2
, b
2
, c
2
, a
3
, b
3
and c
3
.
2. Determine how many digits the decimal
representations of a
n
and c
n
can have. Show that a
n
and c
n
are divisible by 3.
3. Using a list of prime numbers less than 100, show
that b
3
is a prime.
25
AB
a
n
410
n
× 1 b
n
210
n
1× c
n
210
n
× 1+=,=,=
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-9
4. Show that for every integer n > 0, b
n
× c
n
= a
2n
.
5. Deduce the prime factor decomposition of a
6
.
6. Show that GCD(b
n
,c
n
) = GCD(c
n
,2). Deduce that b
n
and c
n
are prime together.
Solution: Begin by entering the three definitions. Type:
DEF(A(N) = 4 · 10
N
–1)
DEF(B(N) = 2 · 10
N
–1)
DEF(C(N) = 2 · 10
N
+1)
Here are the keystrokes for entering the first definition:
First select the DEF command
by pressing .
Now press A
N = 4
10 N
1
Finally press .
Do likewise to define the
other two expressions.
You can now calculate various values of A(N), B(N) and
C(N) simply by typing the defined variable and a value
for N, and then pressing . For example:
A(1) yields 39
A(2) yields 399
A(3) yields 3999
B(1) yields 19
B(2) yields 199
B(3) yields 1999
and so on.
In determining the number of digits the decimal
representations of a
n
and c
n
can have, the calculator is
used only to try out different values of n.
hp40g+.book Page 9 Friday, December 9, 2005 1:03 AM
16-10 Step-by-Step Examples
Show that the whole numbers k such that:
have digits in decimal notation.
We have:
so have digits in decimal notation.
Moreover, is divisible by 9, since its
decimal notation can only end in 9.
We also have:
and
so and are both divisible by 3.
Let’s consider whether B(3) is a prime number.
Type ISPRIME?(B(3))
and press . The
result is 1, which means
true. In other words, B(3) is
a prime.
Note: ISPRIME? is not
available from a CAS soft menu, but you can select it from
from CAS FUNCTIONS menu while you are in the
Equation Writer by pressing , choosing the
INTEGER menu, and scrolling to the ISPRIME? function.
To prove that is a prime number, it is
necessary to show that 1999 is not divisible by any of the
prime numbers less than or equal to . As
, that means testing the divisibility of
1999 by n = 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37,
41. 1999 is not divisible by any of these numbers, so we
can conclude that 1999 is prime.
10
n
k 10
n 1+
< n 1+()
10
n
310
n
a
n
410
n
10
n 1+
<<<<
10
n
b
n
210
n
10
n 1+
<< <
10
n
210
n
c
n
310
n
10
n 1+
<<<<
a
n
b
n
c
n
,, n 1+()
d
n
10
n
1=
a
n
310
n
d
n
+=
c
n
310
n
d
n
=
a
n
c
n
b
3
1999=
1999
1999 2025< 45
2
=
hp40g+.book Page 10 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-11
Now consider the product of two of the definitions
entered above: B(N) × C(N):
B N
C
N .
Press ,
to select EXP2POW and
press .
Press to evaluate
the expression, yielding the
result of B(N) × C(N).
Consider now the decomposition of A(6) into its prime
factors.
Press ,
to select FACTOR and press
.
Now press A 6.
Finally, press to get
the result. The factors are
listed, separated by a
medial period. In this case,
the factors are 3, 23, 29
and 1999.
Now let’s consider whether b
n
and c
n
are relatively prime.
Here, the calculator is useful only for trying out different
values of n.
To show that b
n
and c
n
are relatively prime, it is enough
to note that:
That means that the common divisors of b
n
and c
n
are the
common divisors of b
n
and 2, as well as the common
divisors of c
n
and 2. b
n
and 2 are relatively prime
because b
n
is a prime number other than 2. So:
c
n
b
n
2+=
hp40g+.book Page 11 Friday, December 9, 2005 1:03 AM
16-12 Step-by-Step Examples
Part 2
Given the equation:
[1]
where the integers x and y are unknown and b
3
and c
3
are defined as in part 1 above:
1. Show that [1] has at least one solution.
2. Apply Euclid’s algorithm to b
3
and c
3
and find a
solution to [1].
3. Find all solutions of [1].
Solution: Equation [1] must have at least one solution,
as it is actually a form of Bézout’s Identity.
In effect, Bézout’s Theorem states that if a and b are
relatively prime, there exists an x and y such that:
Therefore, the equation has at least
one solution.
Now enter IEGCD(B(3),
C(3)).
Note that the IEGCD
function can be found on
the INTEGER submenu of
the MATH menu.
Pressing a number
of times returns the result
shown at the right:
In other words:
Therefore, we have a particular solution:
x = 1000, y = –999.
The rest can be done on paper:
,
GCD c
n
b
n
,()GCD c
n
2,()GCD b
n
2,()1===
b
3
xc
3
y 1=+
ax by+1=
b
3
x c
3
y+1=
b
3
1000× c
3
999()×+1=
c
3
b
3
=2+ b
3
999 2 1+×=
hp40g+.book Page 12 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-13
so, , or
The calculator is not needed for finding the general
solution to equation [1].
We started with
and have established that .
So, by subtraction we have:
or
According to Gauss’s Theorem, is prime with , so
is a divisor of .
Hence there exists such that:
and
Solving for x and y, we get:
and
for .
This gives us:
The general solution for all is therefore:
Exercise 7
Let m be a point on the circle C of center O and radius 1.
Consider the image M of m defined on their affixes by the
transformation . When m moves on
b
3
999 c
3
b
3
()1+×=
b
3
1000 c
3
999()×+× 1=
b
3
x c
3
y+1=
b
3
1000× c
3
999()×+1=
b
3
x 1000()c
3
y 999+()+ 0=
b
3
x 1000() c
3
y 999+()=
c
3
b
3
c
3
x 1000()
kZ
x 1000()kc
3
×=
y 999+()kb
3
×=
x 1000 kc
3
×+=
y 999 kb
3
×=
kZ
b
3
xc
3
yb
3
1000 c
3
999()×+× 1==+
kZ
x 1000 kc
3
×+=
y 999 kb
3
×=
F : z >
1
2
---
z
2
Z
hp40g+.book Page 13 Friday, December 9, 2005 1:03 AM
16-14 Step-by-Step Examples
the circle C, M will move on a curve Γ. In this exercise we
will study and plot Γ.
1. Let and m be the point on C of affix
. Find the coordinates of M in terms of t.
2. Compare x(–t) with x(t) and y(–t) with y(t).
3. Compute x(t) and find the variations of x over [0, π].
4. Repeat step 3 for y.
5. Show the variations of x and y in the same table.
6. Put the points of Γ corresponding to t = 0, π/3,
2π/3 and π, and draw the tangent to Γ at these
points.
Part 1 First go to CAS MODES
screen and make t the VX
variable. To do this, press
to open the Equation
Writer, and then press
. This opens
CAS MODES screen. Press and delete the current
variable. Type T and press .
Now enter the expression
and press
to select it.
Now invoke the SUBST
command from the
menu. Because the
expression was
highlighted, the SUBST
command is automatically
applied to it.
Note that the cursor is
positioned in the second
parameter. Since we know
that , we can
enter this as the second
parameter.
t π π[,]
ze
it
=
1
2
---
z
2
z
ze
it
=
hp40g+.book Page 14 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-15
Selecting the entire
expression and pressing
gives the result at
the right:
Now linearize the result by
applying the LIN
command (which can be
found on the menu).
The result, after accepting
the switch to complex
mode, is shown at the right:
Now store the result in
variable M. Note that
STORE is on the
menu.
To calculate the real part of
the expression, apply the
RE command (available on
the COMPLEX submenu of
the MATH menu).
Pressing yields the
result at the right:
We are now going to
define this result as x(t).
To do this, enter =X(t),
highlight the X(t) by
pressing and press
to swap the two
parts of the expression, as
shown at the right:
Now select the entire
expression and apply the
hp40g+.book Page 15 Friday, December 9, 2005 1:03 AM
16-16 Step-by-Step Examples
DEF command to it. Press to complete the
definition.
To calculate the real part of
the expression, apply the
IM command (available on
the COMPLEX submenu of
the MATH menu) to the
stored variable M.
Press to get the
result at the right:
Finally, define the result as
Y(t) in the same way that
you defined X(t): by firstly
adding Y(t) = to the
expression (as shown at the
right) and then applying the DEF command.
We have now found the coordinates of M in terms of t.
Part 2 To find an axis of symmetry for Γ, calculate and
by typing:
X
t
Press to highlight the
expression.
Then press to
produce the result at the
right:
In other words,
Now type Y
t
Press to highlight the
expression.
xt()
yt()
xt() xt()=
hp40g+.book Page 16 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-17
Then press to
produce the result at the
right:
In other words,
.
If is part of , then is also
part of .
Since and are symmetrical with respect to the x-
axis, we can deduce that the x-axis is an axis of symmetry
for .
Part 3 Calculate by typing:
DERVX
X
t. Press
to highlight the
expression.
Pressing returns the
result at the right:
Press to simplify the
result:
You can now define the
function by invoking
DEF.
Note: You will first need to type =X1(t) then exchange
X1(t) with the previous expression.
To do this, highlight X1(t)
and type .
Now select the entire
expression and apply the
DEF command to it:
Finally press to
finish the definition.
yt() yt()=
M
1
xt()yt()(,) Γ M
x
xt()yt()(,)
Γ
M
1
M
2
Γ
x t()
x t()
hp40g+.book Page 17 Friday, December 9, 2005 1:03 AM
16-18 Step-by-Step Examples
Part 4 To calculate , begin
by typing: DERVX(Y(t)).
Pressing returns:
Press again to
simplify the result:
Select FACTOR and press
.
You can now define the
function (in the same
way that you defined
).
Part 5 To show the variations of and , we will trace
and on the same graph.
The independent variable must be t which it should be as
a result of the previous calculations. (You can check this
by pressing .)
Type X(t) in the Equation
Writer and press .
The corresponding
expression is displayed.
Now press , select
Function, press ,
select F1 as the destination and press .
Now do the same thing with Y(t), making F2 the
destination.
To graph the functions, quit
CAS (by pressing ),
choose the Function
aplet, and check F1 and
F2.
y t()
y t()
x t()
xt() yt()
xt() yt()
hp40g+.book Page 18 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-19
Now press to see
the graphs.
Part 6 To find the values of and for
return to CAS, type each function in turn and press
. (You may need to press twice for further
simplification).
For example, pressing
X 0
gives the result at the right:
Likewise, pressing
X 3
gives this
answer at the right:
The other results are:
The slope of the tangents is .
We can find the values of for by
using the lim command.
xt() yt() t 0
π
3
---
2 π
3
----------
π,, ,=
π
X
2π
3
------
⎝⎠
⎛⎞
1
4
---
=
X π()
3
2
---
=
Y 0() 0=
Y
π
3
---
⎝⎠
⎛⎞
3
4
---------
-
=
Y
2π
3
------
⎝⎠
⎛⎞
33
4
-----------------
=
Y π() 0=
m
y' t()
x' t()
----------
=
y' t()
x' t()
----------
t 0
π
3
---
2 π
3
----------
π,, ,=
hp40g+.book Page 19 Friday, December 9, 2005 1:03 AM
16-20 Step-by-Step Examples
The example at the right
shows the case for t = 0.
Select the entire expression
and press to get the
answer:
0
The example at the right
shows the case for t = π/3.
Selecting the entire
expression and pressing
displays the
message shown at the right.
Accept YES and press .
Press again to get
the result:
The next example is for t =
2π/3. Selecting the entire
expression and pressing
displays the result:
0
The final example is for the
case where t = π. Press
, accept YES to the
message UNSIGNED INF.
SOLVE?, press and
press to get the
result:
Here, then, are the variations of and :
xt() yt()
hp40g+.book Page 20 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-21
Now we will graph Γ, which is a parametric curve.
In the Equation Writer, type
X(t) + i × Y(t).
Select the entire expression
and press .
Now press , select
Parametric and press
. Select X1,Y1 as the
destination and press .
To make the graph of Γ, quit CAS and choose the
Parametric aplet. Check X1(T) and Y1(T).
Now press to see
the graph.
t
0
π
0–0+ +0
↓↑↑
0
↓↓↑
0
0–1–0+2
m
0
0
π
3
---
2
π
3
------
x' t()
3
xt()
1
2
------
3
4
------
1
4
---
3
2
---
yt()
3
4
----------
33
4
-------------
y' t()
hp40g+.book Page 21 Friday, December 9, 2005 1:03 AM
16-22 Step-by-Step Examples
Exercise 8 For this exercise, make sure that the calculator is in exact
real mode with X as the current variable.
Part 1 For an integer, n, define the following:
Define g over [0,2] where:
1. Find the variations of g over [0,2]. Show that for
every real x in [0,2]:
2. Show that for every real x in [0,2]:
3. After integration, show that:
4. Using:
show that if has a limit L as n approaches infinity,
then:
u
n
2x 3+
x 2+
---------------
e
x
n
---
xd
0
2
=
gx()
2x 3+
x 2+
---------------
=
3
2
---
gx()
7
4
---
≤≤
3
2
---
e
x
n
---
gx()e
x
n
---
7
4
---
e
x
n
---
≤≤
3
2
---
ne
2
n
---
n
⎝⎠
⎜⎟
⎛⎞
u
n
7
4
---
ne
2
n
---
n
⎝⎠
⎜⎟
⎛⎞
≤≤
e
x
1
x
-------------
x 0
lim 1=
u
n
3 L
7
2
---
≤≤
hp40g+.book Page 22 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-23
Solution 1
Start by defining G(X):
DEF G
X
= 2 X
3
X 2
Now press :
Press and to select
the numerator and
denominator, and then
press . This
leaves G(X) displayed:
Finally, apply the TABVAR
function:
TABVAR
and press a
number of times until
the variation table appears (shown above).
The first line of the variation table gives the sign of
according to x, and the second line the variations
of g (x). Note that for TABVAR the function is always
called F.
We can deduce, then, that g(x) increases over [0, 2].
If you had been in step-by-step mode, you would have
obtained:
Press to get the
result at the right.
g x()
F
2 X 3+
X 2+
--------------------
=
hp40g+.book Page 23 Friday, December 9, 2005 1:03 AM
16-24 Step-by-Step Examples
Now press and scroll down the screen to:
Now press to obtain the table of variations.
If you are not in step-by -step mode, you can also get the
calculation of the derivative by typing:
DERVX(G(X))
which produces the preceding result.
To prove the stated inequality, first calculate g(0) by
typing G(0) and pressing . The answer is: .
Now calculate g(2) by typing G(2) and pressing .
The answer is .
The two results prove that:
for
Solution 2
The calculator is not needed here. Simply stating that:
for
is sufficient to show that, for , we have:
Solution 3
To integrate the preceding
inequality, type the
expression at the right:
Pressing produces
the result at the right:
1
x 2+()
2
-------------------
3
2
---
7
4
---
3
2
---
gx()
7
4
---
≤≤ x 02[,]
e
x
n
---
0 x 02[,]
x 02[,]
3
2
---
e
x
n
---
gx()e
x
n
---
7
4
---
e
x
n
---
≤≤
hp40g+.book Page 24 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-25
We can now see that:
To justify the preceding calculation, we must assume that
is a primitive of .
If you are not sure, you can
use the INTVX function as
illustrated at the right:
Note that the INTVX
command is on the
menu.
The simplified result, got by
pressing twice, is
shown at the right:
Solution 4
To find the limit of when , enter the
expression at the right:
Note that the lim
command is on the
menu. The infinity sign can
be selected from the
character map, opened by
pressing .
Pressing once after selecting the infinity sign adds
a “+” character to the infinity sign.
Select the entire expression
ans press to get the
result, which is:
2
3
2
---
ne
2
n
---
n
⎝⎠
⎜⎟
⎛⎞
u
n
7
4
---
ne
2
n
---
n
⎝⎠
⎜⎟
⎛⎞
≤≤
ne
x
n
---
e
x
n
---
ne
2
n
---
n
⎝⎠
⎜⎟
⎛⎞
n +
hp40g+.book Page 25 Friday, December 9, 2005 1:03 AM
16-26 Step-by-Step Examples
NOTE: The variable VX is now set to N. Reset it to X by
pressing (to display CAS MODES screen)
and change the INDEP VAR setting.
To check the result, we can say that:
and that therefore:
or, simplifying:
If the limit of exists as approaches + in the
inequalities in solution 2 above, we get:
Part 2 1. Show that for every x in [0,2]:
2. Find the value of:
3. Show that for every x in [0,2]:
4. Deduce that:
5. Show that is convergent and find its limit, L.
e
x
1
x
-------------
x 0
lim 1=
e
2
n
---
1
2
n
---
--------------
n +
lim 1=
e
2
n
---
1
⎝⎠
⎜⎟
⎛⎞
n
n +
lim 2=
Lu
n
n
3
2
---
2 L
7
4
---
2≤≤
2x 3+
x 2+
---------------
2
1
x 2+
------------
=
I
2x 3+
x 2+
---------------
dx
0
2
=
1 e
x
n
---
e
2
n
---
≤≤
1 u
n
e
2
n
---
I≤≤
u
n
hp40g+.book Page 26 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-27
Solution 1
Start by defining the
following:
Now type
PROPFRAC(G(X)). Note
that PROPFRAC can be
found on the POLYNOMIAL
submenu of the MATH
menu.
Pressing yields the
result shown at the right.
Solution 2
Enter the integral:
.
Pressing yields the
result shown at the right:
Pressing again
yields:
Working by hand:
, so:
Then, integrating term by term between 0 and 2
produces:
that is, since :
gx() 2
1
x 2+
------------
=
Igx()xd
0
2
=
2x 3+2x 2+()1= gx() 2
1
x 2+
------------
=
gx()x 2xx2+()ln[]=d
0
2
x 2=
x 0=
422ln=ln
gx()x 42ln=d
0
2
hp40g+.book Page 27 Friday, December 9, 2005 1:03 AM
16-28 Step-by-Step Examples
Solution 3
The calculator is not needed here. Simply stating that
increases for is sufficient to yield the
inequality:
Solution 4
Since is positive over [0, 2], through multiplication
we get:
and then, integrating:
Solution 5
First find the limit of
when + .
Note: pressing
after you have selected the
infinity sign from the
character map places a “+”
character in front of the infinity sign.
Selecting the entire
expression and pressing
yields:
1
In effect, tends to 0 as
tends to + , so tends to as tends to + .
As tends to + , is the portion between and a
quantity that tends to .
Hence, converges, and its limit is .
We have therefore shown that:
e
x
n
---
x 02[,]
1 e
x
n
---
e
2
n
---
≤≤
gx()
gx() gx()e
x
n
---
gx()e
2
n
---
≤≤
Iu
n
e
2
n
---
I≤≤
e
2
n
---
n
2
n
---
n
e
2
n
---
e
0
1= n
n u
n
I
I
u
n
I
LI42ln==
hp40g+.book Page 28 Friday, December 9, 2005 1:03 AM
Step-by-Step Examples 16-29
hp40g+.book Page 29 Friday, December 9, 2005 1:03 AM
hp40g+.book Page 30 Friday, December 9, 2005 1:03 AM
Variables and memory management 17-1
17
Variables and memory management
Introduction
The HP 40gs has approximately 200K of user memory.
The calculator uses this memory to store variables,
perform computations, and store history.
A variable is an object that you create in memory to hold
data. The HP 40gs has two types of variables, home
variables and aplet variables.
Home variables are available in all aplets. For
example, you can store real numbers in variables A
to Z and complex numbers in variables Z0 to Z9.
These can be numbers you have entered, or the
results of calculations. These variables are available
within all aplets and within any programs.
Aplet variables apply only to a single aplet. Aplets
have specific variables allocated to them which vary
from aplet to aplet.
You use the calculator’s memory to store the following
objects:
copies of aplets with specific configurations
new aplets that you download
aplet variables
home variables
variables created through a catalog or editor, for
example a matrix or a text note
programs that you create.
You can use the Memory Manager (
MEMORY) to
view the amount of memory available. The catalog views,
which are accessible via the Memory Manager, can be
used to transfer variables such as lists or matrices
between calculators.
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
17-2 Variables and memory management
Storing and recalling variables
You can store numbers or expressions from a previous
input or result into variables.
Numeric Precision A number stored in a variable is always stored as a 12-
digit mantissa with a 3-digit exponent. Numeric precision
in the display, however, depends on the display mode
(Standard, Fixed, Scientific, Engineering, or Fraction). A
displayed number has only the precision that is
displayed. If you copy it from the HOME view display
history, you obtain only the precision displayed, not the
full internal precision. On the other hand, the variable
Ans always contains the most recent result to full
precision.
To store a value 1. On the command line,
enter the value or the
calculation for the result
you wish to store.
2. Press
3. Enter a name for the
variable.
4. Press .
To store the results
of a calculation
If the value you want to store is in the HOME view display
history, for example the results of a previous calculation,
you need to copy it to the command line, then store it.
1. Perform the calculation for the result you want to store.
3 8 6
3
2. Press to highlight to the result you wish to store.
3. Press to copy the result to the command line.
4. Press .
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Variables and memory management 17-3
5. Enter a name for the variable.
A
6. Press to store
the result.
The results of a calculation can also be stored directly to
a variable. For example:
2 5 3
B
To recall a value To recall a variable’s value, type the name of the variable
and press .
A
To use variables in
calculations
You can use variables in calculations. The calculator
substitutes the variable’s value in the calculation:
65 A
To clear a variable You can use the CLRVAR
command to clear a
specified variable. For
example, if you have
stored {1,2,3,4} in variable
L1, entering CLRVAR L1
will clear L1. (You can find the
CLRVAR command
by pressing and choosing the PROMPT
category of commands.)
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
17-4 Variables and memory management
The VARS menu
You use the VARS menu to access all variables in the
calculator. The VARS menu is organised by category. For
each variable category in the left column, there is a list of
variables in the right column. You select a variable
category and then select a variable in the category.
1. Open the VARS menu.
2. Use the arrow keys or press the alpha key of the first
letter in the category to select a variable category.
For example, to select
the Matrix category,
press .
Note: In this instance,
there is no need to
press the ALPHA key.
3. Move the highlight to the variables column.
4. Use the arrow keys to select the variable that you
want. For example, to select the M2 variable, press
.
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Variables and memory management 17-5
5. Choose whether to place the variable name or the
variable value on the command line.
Press to indicate that you want the
variable’s contents to appear on the command
line.
Press to indicate that you want the
variable’s name to appear on the command line.
6. Press to place the value or name on the
command line. The selected object appears on the
command line.
Note: The VARS menu can also be used to enter the
names or values of variables into programs.
Example This example demonstrates how to use the VARS menu to
add the contents of two list variables, and to store the
result in another list variable.
1. Display the List Catalog.
LIST
to select L1
2. Enter the data for L1.
88 90 89
65 70
3. Return to the List Catalog to create L2.
LIST
to select L2
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
17-6 Variables and memory management
4. Enter data for L2.
55 48 86
90 77
5. Press to access HOME.
6. Open the variable menu and select L1.
7. Copy it to the command line. Note: Because the
option is highlighted, the variable’s name,
rather than its contents, is copied to the command
line.
8. Insert the + operator and select the L2 variable from
the List variables.
9. Store the answer in the List catalog L3 variable.
L3
Note: You can also
type list names directly
from the keyboard.
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
Variables and memory management 17-7
Home variables It is not possible to store data of one type in a variable of
another type. For example, you use the Matrix catalog to
create matrices. You can create up to ten matrices, and
you can store these in variables M0 to M9. You cannot
store matrices in variables other than M0 to M9.
Cate-
gory
Available names
Complex Z0 to Z9
For example, (1,2) Z0 or 2+3i
Z1. You can enter a complex
number by typing (r,i), where r represents
the real part, and i represents the
imaginary part.
Graphic G0 to G9
See“Graphic commands” on page 21-21
for more information on storing graphic
objects via programming commands. See
“To store into a graphics variable” on
page 20-5 for more information on
storing graphic object via the sketch view.
Library Aplet library variables can store aplets
that you have created, either by saving a
copy of a standard aplet, or downloading
an aplet from another source.
List L0 to L9
For example, {1,2,3} L1.
Matrix M0 to M9 can store matrices or vectors.
For example, [[1,2],[3,4]] M0.
Modes Modes variables store the modes settings
that you can configure using
MODES.
Notepad Notepad variables store notes.
Program Program variables store programs.
Real A to Z and θ.
For example, 7.45 A.
Symbolic E0…9, S1…S5, s1…s5 and n1…n5.
hp40g+.book Page 7 Friday, December 9, 2005 1:03 AM
17-8 Variables and memory management
Aplet variables Most aplet variables store values that are unique to a
particular aplet. These include symbolic expressions and
equations (see below), settings for the Plot and Numeric
views, and the results of some calculations such as roots
and intersections.
See the Reference Information chapter for more
information about aplet variables.
To access an aplet
variable
1. Open the aplet that contains the variable you want to
recall.
2. Press to display the VARS menu.
3. Use the arrow keys to select a variable category in
the left column, then press to access the variables
in the right column.
4. Use the arrow keys to select a variable in the right
column.
5. To copy the name of the variable onto the edit line,
press . ( is the default setting.)
6. To copy the value of the variable into the edit line,
press and press .
Category Available names
Function F0 to F9 (Symbolic view). See “Function
aplet variables” on page R-7.
Parametric X0, Y0 to X9, Y9 (Symbolic view). See
“Parametric aplet variables” on page
R-8.
Polar R0 to R9 (Symbolic view). See “Polar
aplet variables” on page R-9.
Sequence U0 to U9 (Symbolic view). See
“Sequence aplet variables” on page
R-10.
Solve E0 to E9 (Symbolic view). See “Solve
aplet variables” on page R-11.
Statistics C0 to C9 (Numeric view). See
“Statistics aplet variables” on page
R-12.
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
Variables and memory management 17-9
Memory Manager
You can use the Memory Manager to determine the
amount of available memory on the calculator. You can
also use Memory Manager to organize memory. For
example, if the available memory is low, you can use the
Memory Manager to determine which aplets or variables
consume large amounts of memory. You can make
deletions to free up memory.
Example 1. Start the Memory Manager. A list of variable
categories is displayed.
MEMORY
Free memory is
displayed in the top
right corner and the
body of the screen lists
each category, the memory it uses, and the
percentage of the total memory it uses.
2. Select the category with which you want to work and
press . Memory Manager displays memory
details of variables within the category.
3. To delete variables in a
category:
Press to delete the selected variable.
Press
CLEAR to delete all variables in the
selected category.
hp40g+.book Page 9 Friday, December 9, 2005 1:03 AM
hp40g+.book Page 10 Friday, December 9, 2005 1:03 AM
Matrices 18-1
18
Matrices
Introduction
You can perform matrix calculations in HOME and in
programs. The matrix and each row of a matrix appear
in brackets, and the elements and rows are separated by
commas. For example, the following matrix:
is displayed in the history as:
[[1,2,3],[4,5,6]]
(If the Decimal Mark mode is set to Comma, then separate
each element and each row with a period.)
You can enter matrices directly in the command line, or
create them in the matrix editor.
Vectors Vectors are one-dimensional arrays. They are composed
of just one row. A vector is represented with single
brackets; for example, [1,2,3]. A vector can be a real
number vector or a complex number vector, for example
[(1,2), (7,3)].
Matrices Matrices are two-dimensional arrays. They are composed
of more than one row and more than one column.
Two-dimensional matrices are represented with nested
brackets; for example, [[1,2,3],[4,5,6]]. You can create
complex matrices, for example, [[(1,2), (3,4)], [(4,5),
(6,7)]].
Matrix Variables There are ten matrix variables available, named M0 to
M9. You can use them in calculations in HOME or in a
program. You can retrieve the matrix names from the
VARS menu, or just type their names from the keyboard.
123
456
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
18-2 Matrices
Creating and storing matrices
You can create, edit,
delete, send, and receive
matrices in the Matrix
catalog.
To open the Matrix
catalog, press
MATRIX.
You can also create and store matrices—named or
unnamed—-in HOME. For example, the command:
POLYROOT([1,0,–1,0])XM1
stores the root of the complex vector of length 3 into the
M1 variable. M1 now contains the three roots of
Matrix Catalog
keys
The table below lists the operations of the menu keys in
the Matrix Catalog, as well as the use of Delete ( )
and Clear ( CLEAR).
To create a matrix
in the Matrix
Catalog
1. Press MATRIX to open the Matrix Catalog. The
Matrix catalog lists the 10 available matrix variables,
M0 to M9.
x
3
x–0=
Key Meaning
Opens the highlighted matrix for
editing.
Prompts for a matrix type, then
opens an empty matrix with the
highlighted name.
Transmits the highlighted matrix to
another HP 40gs or a disk drive.
See.
Receives a matrix from another
HP 40gs or a disk drive. See .
Clears the highlighted matrix.
CLEAR Clears all matrices.
or Moves to the end or the beginning
of the catalog.
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Matrices 18-3
2. Highlight the matrix variable name you want to use
and press .
3. Select the type of matrix to create.
For a vector (one-dimensional array),
select Real vector or Complex vector.
Certain operations (+, , CROSS) do not
recognize a one-dimensional matrix as a vector,
so this selection is important.
For a matrix (two-dimensional array),
select Real matrix or Complex matrix.
4. For each element in the matrix, type a number or an
expression, and press . (The expression may
not contain symbolic variable names.)
For complex numbers, enter each number in
complex form; that is, (a, b), where a is the real part
and b is the imaginary part. You must include the
parentheses and the comma.
5. Use the cursor keys to move to a different row or
column. You can change the direction of the highlight
bar by pressing . The menu key toggles
between the following three options:
specifies that the cursor moves to the cell
below the current cell when you press .
specifies that the cursor moves to the cell to
the right of the current cell when you press
.
specifies that the cursor stays in the current
cell when you press .
6. When done, press
MATRIX to see the Matrix
catalog, or press to return to HOME. The
matrix entries are automatically stored.
A matrix is listed with two dimensions, even if it is 3×1. A
vector is listed with the number of elements, such as 3.
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18-4 Matrices
To transmit a
matrix
You can send matrices between calculators just as you
can send aplets, programs, lists, and notes.
1. Connect the calculators using an appropriate cable.
2. Open the Matrix catalogs on both calculators.
3. Highlight the matrix to send.
4. Press and choose the method of sending.
5. Press on the receiving calculator and choose
the method of receiving.
For more information on sending and receiving files, see
“Sending and receiving aplets” on page 22-4.
Working with matrices
To edit a matrix In the Matrix catalog, highlight the name of the matrix
you want to edit and press .
Matrix edit keys The following table lists the matrix edit key operations.
Key Meaning
Copies the highlighted element to
the edit line.
Inserts a row of zeros above, or a
column of zeros to the left, of the
highlighted cell. (You are prompted
to choose row or column.)
A three-way toggle for cursor
advancement in the Matrix editor.
advances to the right, ¸
advances downward, and
does not advance at all.
Switches between larger and
smaller font sizes.
Deletes the highlighted cells, row,
or column (you are prompted to
make a choice).
CLEAR Clears all elements from the matrix.
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Matrices 18-5
To display a matrix In the Matrix catalog ( MATRIX), highlight the
matrix name and press .
In HOME, enter the name of the matrix variable and
press .
To display one
element
In HOME, enter matrixname(row,column). For example,
if M2 is [[3,4],[5,6]], then M2(1,2) returns
4.
To create a matrix
in HOME
1. Enter the matrix in the edit line. Start and end the
matrix and each row with square brackets (the shifted
and keys).
2. Separate each element and each row with a comma.
Example: [[1,2],[3,4]].
3. Press to enter and display the matrix.
The left screen below shows the matrix
[[2.5,729],[16,2]] being stored into M5. The
screen on the right shows the vector [66,33,11] being
stored into M6. Note that you can enter an expression
(like 5/2) for an element of the matrix, and it will be
evaluated.
Moves to the first row, last row, first
column, or last column respectively.
Key Meaning (Continued)
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18-6 Matrices
To store one
element
In HOME, enter, value matrixname(row,column).
For example, to change the element in the first row and
second column of M5 to 728, then display the resulting
matrix:
728
M512
M5 .
An attempt to store an element to a row or column beyond
the size of the matrix results in an error message.
Matrix arithmetic
You can use the arithmetic functions (+, –, ×, / and
powers) with matrix arguments. Division left-multiplies by
the inverse of the divisor. You can enter the matrices
themselves or enter the names of stored matrix variables.
The matrices can be real or complex.
For the next examples, store [[1,2],[3,4]] into M1 and
[[5,6],[7,8]] into M2.
Example 1. Create the first matrix.
MATRIX
1 2
3 4
2. Create the second
matrix.
MATRIX
5 6
7
8
3. Add the matrices that
you created.
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Matrices 18-7
M1 M2
To multiply and
divide by a scalar
For division by a scalar, enter the matrix first, then the
operator, then the scalar. For multiplication, the order of
the operands does not matter.
The matrix and the scalar can be real or complex. For
example, to divide the result of the previous example by
2, press the following keys:
2
To multiply two
matrices
To multiply the two matrices M1 and M2 that you created
for the previous example, press the following keys:
M1 M
2
To multiply a matrix by a
vector, enter the matrix
first, then the vector. The
number of elements in the vector must equal the number
of columns in the matrix.
To raise a matrix to
a power
You can raise a matrix to any power as long as the power
is an integer. The following example shows the result of
raising matrix M1, created earlier, to the power of 5.
M1 5
Note: You can also raise a
matrix to a power without
first storing it as a variable.
Matrices can be raised to negative powers. In this case,
the result is equivalent to 1/[matrix]^ABS(power). In the
following example, M1 is raised to the power of –2.
M1
2
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18-8 Matrices
To divide by a
square matrix
For division of a matrix or a vector by a square matrix,
the number of rows of the dividend (or the number of
elements, if it is a vector) must equal the number of rows
in the divisor.
This operation is not a mathematical division: it is a left-
multiplication by the inverse of the divisor. M1/M2 is
equivalent to M2
–1
* M1.
To divide the two matrices M1 and M2 that you created
for the previous example, press the following keys:
M1
M2
To invert a matrix You can invert a square matrix in HOME by typing the
matrix (or its variable name) and pressing x
–1
. Or you can use the matrix INVERSE command.
Enter INVERSE(matrixname) in HOME and press
.
To negate each
element
You can change the sign of each element in a matrix by
pressing before the matrix name.
Solving systems of linear equations
Example Solve the following linear system:
1. Open the Matrix
catalog and create a
vector.
MATRIX
2. Create the vector of the
constants in the linear
system.
5 7
1
2x 3y 4z++ 5
xyz+7
4xy–2z+1
=
=
=
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Matrices 18-9
3. Return to the Matrix
Catalog.
MATRIX
In this example, the
vector you created is
listed as M1.
4. Create a new matrix.
Select Real matrix
5. Enter the equation
coefficients.
23
4
11
1 4
12
In this example, the matrix you created is listed as
M2.
6. Return to HOME and enter the calculation to
left-multiply the constants vector by the inverse of the
coefficients matrix.
M2
x
–1
M1
The result is a vector of the
solutions x = 2, y = 3 and z = –2.
An alternative method, is to use the RREF function. See
“RREF” on page 18-12.
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18-10 Matrices
Matrix functions and commands
About functions Functions can be used in any aplet or in HOME. They
are listed in the MATH menu under the Matrix
category. They can be used in mathematical
expressions—primarily in HOME—as well as in
programs.
Functions always produce and display a result. They
do not change any stored variables, such as a matrix
variable.
Functions have arguments that are enclosed in
parentheses and separated by commas; for example,
CROSS(vector1,vector2). The matrix input can be
either a matrix variable name (such as M1) or the
actual matrix data inside brackets. For example,
CROSS(M1,[1,2]).
About commands Matrix commands are listed in the CMDS menu (
CMDS), in the matrix category.
See “Matrix commands” on page 21-24 for details of the
matrix commands available for use in programming.
Functions differ from commands in that a function can be
used in an expression. Commands cannot be used in an
expression.
Argument conventions
For row# or column#, supply the number of the row
(counting from the top, starting with 1) or the number
of the column (counting from the left, starting with 1).
The argument matrix can refer to either a vector or a
matrix.
Matrix functions
COLNORM Column Norm. Finds the maximum value (over all
columns) of the sums of the absolute values of all elements
in a column.
COLNORM(matrix)
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Matrices 18-11
COND Condition Number. Finds the 1-norm (column norm) of a
square matrix.
COND(matrix)
CROSS Cross Product of vector1 with vector2.
CROSS(vector1, vector2)
DET Determinant of a square matrix.
DET(matrix)
DOT Dot Product of two arrays, matrix1 matrix2.
DOT(matrix1, matrix2)
EIGENVAL Displays the eigenvalues in vector form for matrix.
EIGENVAL(matrix)
EIGENVV Eigenvectors and Eigenvalues for a square matrix.
Displays a list of two arrays. The first contains the
eigenvectors and the second contains the eigenvalues.
EIGENVV(matrix)
IDENMAT Identity matrix. Creates a square matrix of dimension
size × size whose diagonal elements are 1 and off-
diagonal elements are zero.
IDENMAT(size)
INVERSE Inverts a square matrix (real or complex).
INVERSE(matrix)
LQ LQ Factorization. Factors an m × n matrix into three
matrices:
{[[ m × n lowertrapezoidal]],[[ n × n orthogonal]],
[[ m × m permutation]]}.
LQ(matrix)
LSQ Least Squares. Displays the minimum norm least squares
matrix (or vector).
LSQ(matrix1, matrix2)
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18-12 Matrices
LU LU Decomposition. Factors a square matrix into three
matrices:
{[[lowertriangular]],[[uppertriangular]],[[permutation]]}
The uppertriangular has ones on its diagonal.
LU(matrix)
MAKEMAT Make Matrix. Creates a matrix of dimension rows ×
columns, using expression to calculate each element. If
expression contains the variables I and J, then the
calculation for each element substitutes the current row
number for I and the current column number for J.
MAKEMAT(expression, rows, columns)
Example
MAKEMAT(0,3,3) returns a 3×3 zero matrix,
[[0,0,0],[0,0,0],[0,0,0]].
QR QR Factorization. Factors an m×n matrix into three
matrices: {[[m×m orthogonal]],[[m×n
uppertrapezoidal]],[[n×n permutation]]}.
QR(matrix)
RANK Rank of a rectangular matrix.
RANK(matrix)
ROWNORM Row Norm. Finds the maximum value (over all rows) for
the sums of the absolute values of all elements in a row.
ROWNORM(matrix)
RREF Reduced-Row Echelon Form. Changes a rectangular
matrix to its reduced row-echelon form.
RREF(matrix)
SCHUR Schur Decomposition. Factors a square matrix into two
matrices. If matrix is real, then the result is
{[[orthogonal]],[[upper-quasi triangular]]}.
If matrix is complex, then the result is
{[[unitary]],[[upper-triangular]]}.
SCHUR(matrix)
SIZE Dimensions of matrix. Returned as a list: {rows,columns}.
SIZE(matrix)
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Matrices 18-13
SPECNORM Spectral Norm of matrix.
SPECNORM(matrix)
SPECRAD Spectral Radius of a square matrix.
SPECRAD(matrix)
SVD Singular Value Decomposition. Factors an m × n matrix
into two matrices and a vector:
{[[m × m square orthogonal]],[[n × n square orthogonal]],
[real]}.
SVD(matrix)
SVL Singular Values. Returns a vector containing the singular
values of matrix.
SVL(matrix)
TRACE Finds the trace of a square matrix. The trace is equal to
the sum of the diagonal elements. (It is also equal to the
sum of the eigenvalues.)
TRACE(matrix)
TRN Transposes matrix. For a complex matrix, TRN finds the
conjugate transpose.
TRN(matrix)
Examples
Identity Matrix You can create an identity matrix with the IDENMAT
function. For example, IDENMAT(2) creates the 2×2
identity matrix [[1,0],[0,1]].
You can also create an identity matrix using the
MAKEMAT (make matrix) function. For example, entering
MAKEMAT(I¼J,4,4) creates a 4 ×
4 matrix showing the
numeral 1 for all elements except zeros on the diagonal.
The logical operator ¼ returns 0 when I (the row number)
and J (the column number) are equal, and returns 1 when
they are not equal.
Transposing a
Matrix
The TRN function swaps the row-column and column-row
elements of a matrix. For instance, element 1,2 (row 1,
hp40g+.book Page 13 Friday, December 9, 2005 1:03 AM
18-14 Matrices
column 2) is swapped with element 2,1; element 2,3 is
swapped with element 3,2; and so on.
For example, TRN([[1,2],[3,4]]) creates the matrix
[[1,3],[2,4]].
Reduced-Row
Echelon Form
The following set of equations
can be written as the augmented matrix
which can then stored as a
real matrix in any
matrix variable. M1 is used
in this example.
You can use the RREF
function to change this to
reduced row echelon form,
storing it in any matrix
variable. M2 is used in this
example.
The reduced row echelon
matrix gives the solution to
the linear equation in the
fourth column.
An advantage of using the
RREF function is that it will also work with inconsistent
matrices resulting from systems of equations which have
no solution or infinite solutions.
For example, the following set of equations has an infinite
number of solutions:
x 2y–3z+14
2xyz+3
4x
2y–2z+14
=
=
=
12–314
21 1–3
42–214
34×
xyz+5
2xy–7
x 2y z+2
=
=
=
hp40g+.book Page 14 Friday, December 9, 2005 1:03 AM
Matrices 18-15
The final row of zeros in the
reduced-row echelon form
of the augmented matrix
indicates an inconsistent
system with infinite
solutions.
hp40g+.book Page 15 Friday, December 9, 2005 1:03 AM
hp40g+.book Page 16 Friday, December 9, 2005 1:03 AM
Lists 19-1
19
Lists
You can do list operations in HOME and in programs. A
list consists of comma-separated real or complex
numbers, expressions, or matrices, all enclosed in braces.
A list may, for example, contain a sequence of real
numbers such as {1,2,3}. (If the Decimal Mark mode is
set to Comma, then the separators are periods.) Lists
represent a convenient way to group related objects.
There are ten list variables available, named L0 to L9. You
can use them in calculations or expressions in HOME or
in a program. Retrieve the list names from the VARS
menu, or just type their names from the keyboard.
You can create, edit, delete, send, and receive named
lists in the List catalog (
LIST). You can also create
and store lists—named or unnnamed—in HOME lists
List variables are identical in behaviour to the columns
C1.C0 in the Statistics aplet. You can store a statistics
column to a list (or vice versa) and use any of the list
functions on the statistics columns, or the statistics
functions, on the list variables.
Create a list in
the List Catalog
1. Open the List catalog.
LIST.
2. Highlight the list name
you want to assign to
the new list (L1, etc.)
and press to
display the List editor.
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
19-2 Lists
3. Enter the values you want in the list, pressing
after each one.
Values can be real or
complex numbers (or
an expression). If you
enter a calculation, it is
evaluated and the
result is inserted in the
list.
4. When done, press
LIST to see the List catalog,
or press to return to HOME.
List catalog keys The list catalog keys are:
Key Meaning
Opens the highlighted list for
editing.
Transmits the highlighted list to
another HP 40gs or a PC. See
“Sending and receiving aplets” on
page 22-4 for further information.
Receives a list from another
HP 40gs or a PC. See “Sending
and receiving aplets” on page 22-4
for further information.
Clears the highlighted list.
CLEAR Clears all lists.
or Moves to the end or the beginning
of the catalog.
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Lists 19-3
List edit keys When you press to create or change a list, the
following keys are available to you:
Create a list in
HOME
1. Enter the list on the edit line. Start and end the list
with braces (the shifted and keys) and
separate each element with a comma.
2. Press to evaluate and display the list.
Immediately after typing in the list, you can store it in
a variable by pressing listname . The
list variable names are L0 through L9.
This example stores the
list {25,147,8} in L1.
Note: You can omit the
final brace when
entering a list.
Key Meaning
Copies the highlighted list item into
the edit line.
Inserts a new value before the
highlighted item.
Deletes the highlighted item from
the list.
CLEAR Clears all elements from the list.
or Moves to the end or the beginning
of the list.
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19-4 Lists
Displaying and editing lists
To display a list In the List catalog, highlight the list name and press
.
In HOME, enter the name of the list and press
.
To display one
element
In HOME, enter listname(element#). For example, if L2 is
{3,4,5,6}, then L2(2) returns 4.
To edit a list 1. Open the List catalog.
LIST.
2. Press or to highlight the name of the list you
want to edit (L1, etc.) and press to display the
list contents.
3. Press or to highlight the element you want to
edit. In this example, edit the third element so that it
has a value of 5.
5
4. Press .
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Lists 19-5
To insert an element
in a list
1. Open the List catalog.
LIST.
2. Press or to
highlight the name of
the list you want to edit
(L1, etc.) and press
to display the list
contents.
New elements are inserted above the highlighted
position. In this example, an element, with the value
of 9, is inserted between the first and second
elements in the list.
3. Press to the
insertion position, then
press , and press
9.
4. Press .
To store one
element
In HOME, enter value listname(element). For
example, to store 148 as the second element in L1, type
148 L1(2) .
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
19-6 Lists
Deleting lists
To delete a list In the List catalog, highlight the list name and press .
You are prompted to confirm that you want to delete the
contents of the highlighted list variable. Press to
delete the contents.
To delete all lists In the List catalog, press CLEAR.
Transmitting lists
You can send lists to calculators or PCs just as you can
aplets, programs, matrices, and notes.
1. Connect the calculators using an appropriate cable).
2. Open the List catalogs on both calculators.
3. Highlight the list to send.
4. Press and choose the method of sending.
5. Press on the receiving calculator and choose
the method of receiving.
For more information on sending and receiving files, see
“Sending and receiving aplets” on page 22-4.
List functions
List functions are found in the MATH menu. You can use
them in HOME, as well as in programs.
You can type in the name
of the function, or you can
copy the name of the
function from the List
category of the MATH
menu. Press (the
alpha L character key). This
highlights the List category in the left column. Press to
move the cursor to the right column which contain the List
functions, select a function, and press .
List functions have the following syntax:
Functions have arguments that are enclosed in
parentheses and separated by commas. Example:
CONCAT(L1,L2). An argument can be either a list
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
Lists 19-7
variable name (such as L1) or the actual list. For
example, REVERSE({1,2,3}).
If Decimal Mark in Modes is set to Comma, use
periods to separate arguments. For example,
CONCAT(L1.L2).
Common operators like +, –, ×, and / can take lists as
arguments. If there are two arguments and both are lists,
then the lists must have the same length, since the
calculation pairs the elements. If there are two arguments
and one is a real number, then the calculation pairs the
number with each element of the list.
Example
5*{1,2,3} returns {5,10,15}.
Besides the common operators that can take numbers,
matrices, or lists as arguments, there are commands that
can only operate on lists.
CONCAT Concatenates two lists into a new list.
CONCAT(list1,list2)
Example
CONCAT({1,2,3},{4}) returns {1,2,3,4}.
ΔLIST Creates a new list composed of the first differences, that
is, the differences between the sequential elements in
list1. The new list has one fewer elements than list1. The
first differences for {x
1
x
2
... x
n
} are {x
2
–x
1
... x
n
–x
n–1
}.
ΔLIST(list1)
Example
In HOME, store {3,5,8,12,17,23} in L5 and find the first
differences for the list.
{3,5,8,12,17,23
}
L 5
L
Select ΔLIST
L5
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19-8 Lists
MAKELIST Calculates a sequence of elements for a new list.
Evaluates expression with variable from begin to end
values, taken at increment steps.
MAKELIST(expression,variable,begin,end,
increment)
The MAKELIST function generates a series by
automatically producing a list from the repeated
evaluation of an expression.
Example
In HOME, generate a series of squares from 23 to 27.
L Select
MAKELIST
A
A 23
27 1
ΠLIST Calculates the product of all elements in list.
ΠLIST(list)
Example
ΠLIST({2,3,4}) returns 24.
POS Returns the position of an element within a list. The
element can be a value, a variable, or an expression. If
there is more than one instance of the element, the
position of the first occurrence is returned. A value of 0 is
returned if there is no occurrence of the specified element.
POS(list, element)
Example
POS ({3, 7, 12, 19},12) returns 3
REVERSE Creates a list by reversing the order of the elements in a
list.
REVERSE(list)
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Lists 19-9
SIZE Calculates the number of elements in a list.
SIZE(list)
Also works with matrices.
ΣLIST Calculates the sum of all elements in list.
ΣLIST(list)
Example
ΣLIST({2,3,4}) returns 9.
SORT Sorts elements in ascending order.
SORT(list)
Finding statistical values for list elements
To find values such as the mean, median, maximum, and
minimum values of the elements in a list, use the Statistics
aplet.
Example In this example, use the Statistics aplet to find the mean,
median, maximum, and minimum values of the elements
in the list, L1.
1. Create L1 with values 88, 90, 89, 65, 70, and 89.
{ 88 90
89 65 70 89
}
L1
2. In HOME, store L1 into
C1. You will then be
able to see the list data in the Numeric view of the
Statistics aplet.
L1
C1
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19-10 Lists
3. Start the Statistics aplet, and select 1-variable mode
(press , if necessary, to display ).
Select
Statistics
Note: Your list values are now in column 1 (C1).
4. In the Symbolic view, define H1 (for example) as C1
(sample) and 1 (frequency).
5. Go to the Numeric view to display calculated
statistics.
See “One-variable” on page 10-14 for the meaning
of each computed statistic.
hp40g+.book Page 10 Friday, December 9, 2005 1:03 AM
Notes and sketches 20-1
20
Notes and sketches
Introduction
The HP 40gs has text and picture editors for entering
notes and sketches.
Each aplet has its own independent Note view and
Sketch view. Notes and sketches that you create in
these views are associated with the aplet. When you
save the aplet, or send it to another calculator, the
notes and sketches are saved or sent as well.
The Notepad is a collection of notes independent of
all aplets. These notes can also be sent to another
calculator via the Notepad Catalog.
Aplet note view
You can attach text to an aplet in its Note view.
To write a note in
Note view
1. In an aplet, press NOTE for the Note view.
2. Use the note editing keys shown in the table in the
following section.
3. Set Alpha lock ( ) for quick entry of letters. For
lowercase Alpha lock, press .
4. While Alpha lock is on:
To type a single letter of the opposite case, press
letter.
To type a single non-alpha character (such as 5
or [ ), press first. (This turns off Alpha
lock for one character.)
Your work is automatically saved. Press any view key
( , , , ) or to exit
the Notes view.
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20-2 Notes and sketches
Note edit keys
Key Meaning
Space key for text entry.
Displays next page of a multi-page
note.
Alpha-lock for letter entry.
Lower-case alpha-lock for letter
entry.
Backspaces cursor and deletes
character.
Deletes current character.
Starts a new line.
CLEAR Erases the entire note.
Menu for entering variable names,
and contents of variables.
Menu for entering math
operations, and constants.
CMDS
Menu for entering program
commands.
CHARS
Displays special characters. To
type one, highlight it and press
. To copy a character without
closing the CHARS screen, press
.
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Notes and sketches 20-3
Aplet sketch view
You can attach pictures to an aplet in its Sketch view
( SKETCH). Your work is automatically saved with the
aplet. Press any other view key or to exit the
Sketch view
Sketch keys
To draw a line
1. In an aplet, press SKETCH for the Sketch view.
2. In Sketch view, press and move the cursor to
where you want to start the line
3. Press . This turns on line-drawing.
4. Move the cursor in any direction to the end point of
the line by pressing the , , , keys.
5. Press to finish the line.
Key Meaning
Stores the specified portion of the
current sketch to a graphics
variable (G1 through G0).
Adds a new, blank page to the
current sketch set.
Displays next sketch in the sketch
set. Animates if held down.
Opens the edit line to type a text
label.
Displays the menu-key labels for
drawing.
Deletes the current sketch.
CLEAR Erases the entire sketch set.
Toggles menu key labels on and
off. If menu key labels are hidden,
or any menu key, redisplays
the menu key labels.
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20-4 Notes and sketches
To draw a box 1. In Sketch view, press and move the cursor to
where you want any corner of the box to be.
2. Press .
3. Move the cursor to mark the opposite corner for the
box. You can adjust the size of the box by moving the
cursor.
4. Press to finish the box.
To draw a circle 1. In Sketch view, press and move the cursor to
where you want the center of the circle to be.
2. Press . This turns on circle drawing.
3. Move the cursor the distance of the radius.
4. Press to draw the circle.
DRAW keys
Key Meaning
Dot on. Turns pixels on as the cursor
moves.
Dot off. Turns pixels off as the cursor
moves.
Draws a line from the cursor’s starting
position to the cursor’s current position.
Press when you have finished. You
can draw a line at any angle.
Draws a box from the cursor’s starting
position to the cursor’s current position.
Press when you have finished.
Draws a circle with the cursor’s starting
position as the center. The radius is the
distance between the cursor’s starting
and ending position. Press to draw
the circle.
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Notes and sketches 20-5
To label parts of a
sketch
1. Press and type the text on the edit line. To lock
the Alpha shift on, press (for uppercase) or
(for lowercase).
To make the label a smaller character size, turn off
before pressing . ( is a toggle
between small and large font size). The smaller
character size cannot display lowercase letters.
2. Press .
3. Position the label where you want it by pressing the
, , , keys.
4. Press again to affix the label.
5. Press to continue
drawing, or press
to exit the
Sketch view.
To create a set of
sketches
You can create a set of up to ten sketches. This allows for
simple animation.
After making a sketch, press to add a new,
blank page. You can now make a new sketch, which
becomes part of the current set of sketches.
To view the next sketch in an existing set, press
. Hold down for animation.
To remove the current page in the current sketch
series, press .
To store into a
graphics variable
You can define a portion of a sketch inside a box, and
then store that graphic into a graphics variable.
1. In the Sketch view, display the sketch you want to
copy (store into a variable).
2. Press .
3. Highlight the variable name you want to use and
press .
4. Draw a box around the portion you want to copy:
move the cursor to one corner, press , then move
the cursor to the opposite corner, and press .
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
20-6 Notes and sketches
To import a
graphics variable
You can copy the contents of a graphics variable into the
Sketch view of an aplet.
1. Open the Sketch view of the aplet (
SKETCH).
The graphic will be copied here.
2. Press , .
3. Highlight Graphic, then press and highlight the
name of the variable (G1, etc.).
4. Press to recall the contents of the graphics
variable.
5. Move the box to where you would like to copy the
graphic, then press .
The notepad
Subject to available memory, you can store as many
notes as you want in the Notepad (
NOTEPAD).
These notes are independent of any aplet. The Notepad
catalog lists the existing entries by name. It does not
include notes that were created in aplets’ Note views, but
these can be imported. See “To import a note” on
page 20-8.
To create a note in
the Notepad
1. Display the Notepad
catalog.
NOTEPAD
2. Create a new note.
3. Enter a name for your
note.
MYNOTE
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
Notes and sketches 20-7
4. Write your note.
See “Note edit keys
on page 20-2 for more
information on the
entry and editing of
notes.
5. When you are finished, press or an aplet key
to exit Notepad. Your work is automatically saved.
Notepad Catalog keys
Key Meaning
Opens the selected note for
editing.
Begins a new note, and asks
for a name.
Transmits the selected note to
another HP 40gs or PC.
Receives a note being
transmitted from another HP
40gs or PC.
Deletes the selected note.
CLEAR Deletes all notes in the
catalog.
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20-8 Notes and sketches
To import a note You can import a note from the Notepad into an aplet’s
Note view, and vice versa. Suppose you want to copy a
note named “Assignments” from the Notepad into the
Function Note view:
1. In the Function aplet, display the Note view
(
NOTE).
2. Press , highlight Notepad in the left
column, then highlight the name “Assignments” in the
right column.
3. Press to copy the contents of
Assignments” to the Function Note view.
Note: To recall the name instead of the contents,
press instead of .
Suppose you want to copy the Note view from the current
aplet into the note, Assignments, in the Notepad.
1. In the Notepad (
NOTEPAD), open the note,
Assignments.
2. Press , highlight Note in the left
column, then press and highlight NoteText in
the right column.
3. Press to recall the contents of the Note
view into the note “Assignments.
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
Programming 21-1
21
Programming
Introduction
This chapter describes how to program using the HP
40gs. In this chapter you’ll learn about:
using the Program catalog to create and edit
programs
programming commands
storing and retrieving variables in programs
programming variables.
HINT
More information on programming, including examples
and special tools, can be found at HP’s calculators web
site:
http://www.hp.com/calculators
The Contents of a
Program
An HP 40gs program contains a sequence of numbers,
mathematical expressions, and commands that execute
automatically to perform a task.
These items are separated by a colon ( : ). Commands
that take multiple arguments have those arguments
separated by a semicolon ( ; ). For example,
PIXON xposition;yposition:
Structured
Programming
Inside a program you can use branching structures to
control the execution flow. You can take advantage of
structured programming by creating building-block
programs. Each building-block program stands
alone—and it can be called from other programs. Note:
If a program has a space in its name then you have to put
quotes around it when you want to run it.
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21-2 Programming
Example RUN GETVALUE: RUN CALCULATE: RUN
"SHOW ANSWER":
This program is separated into three main tasks, each an
individual program. Within each program, the task can
be simple—or it can be divided further into other
programs that perform smaller tasks.
Program catalog
The Program catalog is where you create, edit, delete,
send, receive, or run programs. This section describes
how to
open the Program catalog
create a new program
enter commands from the program commands menu
enter functions from the MATH menu
edit a program
run and debug a program
stop a program
copy a program
send and receive a program
delete a program or its contents
customize an aplet.
Open Program
Catalog
1. Press PROGRM.
The Program Catalog displays a list of program
names. The Program Catalog contains a built-in entry
called Editline.
Editline contains the last expression that you
entered from the edit line in HOME, or the last data
you entered in an input form. (If you press
from HOME without entering any data, the HP 40gs
runs the contents of Editline.)
Before starting to work with programs, you should
take a few minutes to become familiar with the
Program catalog menu keys. You can use any of the
following keys (both menu and keyboard), to perform
tasks in the Program catalog.
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Programming 21-3
Program catalog keys
The program catalog keys are:
Key Meaning
Opens the highlighted program
for editing.
Prompts for a new program
name, then opens an empty
program.
Transmits the highlighted
program to another HP 40gs or to
a disk drive.
Receives the highlighted program
from another HP 40gs or from a
disk drive.
Runs the highlighted program.
or Moves to the beginning or end of
the Program catalog.
Deletes the highlighted program.
CLEAR Deletes all programs in the
program catalog.
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21-4 Programming
Creating and editing programs
Create a new
program
1. Press PROGRM to open the Program catalog.
2. Press .
The HP 40gs prompts
you for a name.
A program name can contain special characters,
such as a space. However, if you use special
characters and then run the program by typing it in
HOME, you must enclose the program name in
double quotes (" "). Don't use the " symbol within your
program name.
3. Type your program
name, then press .
When you press ,
the Program Editor
opens.
4. Enter your program. When done, start any other
activity. Your work is saved automatically.
Enter commands Until you become familiar with the HP 40gs commands,
the easiest way to enter commands is to select them from
the Commands menu from the Program editor. You can
also type in commands using alpha characters.
1. From the Program editor, press
CMDS to open
the Program Commands menu.
CMDS
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Programming 21-5
2. On the left, use or to highlight a command
category, then press to access the commands in
the category. Select the command that you want.
3. Press to paste the command into the program
editor.
Edit a program 1. Press PROGRM to
open the Program
catalog.
2. Use the arrow keys to highlight the program you want
to edit, and press . The HP 40gs opens the
Program Editor. The name of your program appears
in the title bar of the display. You can use the
following keys to edit your program.
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21-6 Programming
Editing keys The editing keys are:
Key Meaning
Inserts the character at the
editing point.
Inserts space into text.
Displays previous page of the
program.
Displays next page of the program.
Moves up or down one line.
Moves right or left one character.
Alpha-lock for letter entry. Press
A...Z to lock lower case.
Backspaces cursor and deletes
character.
Deletes current character.
Starts a new line.
CLEAR Erases the entire program.
Displays menus for selecting variable
names, contents of variables, math
functions, and program constants.
CMDS Displays menus for selecting program
conmmands.
CHARS Displays all characters. To type one,
highlight it and press .
To enter several characters in a row,
use the menu key while in the
CHARS menu.
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
Programming 21-7
Using programs
Run a program From HOME, type RUN program_name.
or
From the Program catalog, highlight the program you
want to run and press
Regardless of where you start the program, all programs
run in HOME. What you see will differ slightly depending
on where you started the program. If you start the
program from HOME, the HP 40gs displays the contents
of Ans (Home variable containing the last result), when
the program has finished. If you start the program from
the Program catalog, the HP 40gs returns you to the
Program catalog when the program ends.
Debug a
program
If you run a program that contains errors, the program
will stop and you will see an error message.
To debug the program:
1. Press to edit the program.
The insert cursor appears in the program at the point
where the error occurred.
2. Edit the program to fix the error.
3. Run the program.
4. Repeat the process until you correct all errors.
Stop a program You can stop the running of a program at any time by
pressing CANCEL (the key). Note: You may have to
press it a couple of times.
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21-8 Programming
Copy a program You can use the following procedure if you want to make
a copy of your work before editing—or if you want to use
one program as a template for another.
1. Press
PROGRM to open the Program catalog.
2. Press .
3. Type a new file name, then choose .
The Program Editor opens with a new program.
4. Press to open the variables menu.
5. Press to quickly scroll to Program.
6. Press , then highlight the program you want to
copy.
7. Press , then press .
The contents of the highlighted program are copied
into the current program at the cursor location.
HINT
If you use a programming routine often, save the routine
under a different program name, then use the above
method to copy it into your programs.
Transmit a
program
You can send programs to, and receive programs from,
other calculators just as you can send and receive aplets,
matrices, lists, and notes.
After connecting the calculators with an appropriate
cable, open the Program catalogs on both calculators.
Highlight the program to send, then press on the
sending calculator and on the receiving calculator.
You can also send programs to, and receive programs
from, a remote storage device (aplet disk drive or
computer). This takes place via a cable connection and
requires an aplet disk drive or specialized software
running on a PC (such as a connectivity kit).
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
Programming 21-9
Delete a
program
To delete a program:
1. Press PROGRM to open the Program catalog.
2. Highlight a program to delete, then press .
Delete all
programs
You can delete all programs at once.
1. In the Program catalog, press CLEAR.
2. Press .
Delete the
contents of a
program
You can clear the contents of a program without deleting
the program name.
1. Press
PROGRM to open the Program catalog.
2. Highlight a program, then press .
3. Press
CLEAR, then press .
4. The contents of the program are deleted, but the
program name remains.
Customizing an aplet
You can customize an aplet and develop a set of
programs to work with the aplet.
Use the SETVIEWS command to create a custom VIEWS
menu which links specially written programs to the new
aplet.
A useful method for customizing an aplet is illustrated
below:
1. Decide on the built-in aplet that you want to
customize. For example you could customize the
Function aplet or the Statistics aplet. The customized
aplet inherits all the properties of the built-in aplet.
Save the customized aplet with a unique name.
2. Customize the new aplet if you need to, for example
by presetting axes or angle measures.
3. Develop the programs to work with your customized
aplet. When you develop the aplet’s programs, use
the standard aplet naming convention. This allows
you to keep track of the programs in the Program
catalog that belong to each aplet. See “Aplet naming
convention” on page 21-10.
hp40g+.book Page 9 Friday, December 9, 2005 1:03 AM
21-10 Programming
4. Develop a program that uses the SETVIEWS
command to modify the aplet’s VIEWS menu. The
menu options provide links to associated programs.
You can specify any other programs that you want
transferred with the aplet. See “SETVIEWS” on page
21-14 for information on the command.
5. Ensure that the customized aplet is selected, then run
the menu configuration program to configure the
aplet’s VIEWS menu.
6. Test the customized aplet and debug the associated
programs. (Refer to “Debug a program” on page
16-7).
Aplet naming convention
To assist users in keeping track of aplets and associated
programs, use the following naming convention when
setting up an aplet’s programs:
Start all program names with an abbreviation of the
aplet name. We will use APL in this example.
Name programs called by menu entries in the VIEWS
menu number, after the entry, for example:
APL.ME1 for the program called by menu option
1
APL.ME2 for the program called by menu option
2
Name the program that configures the new VIEWS
menu option APL.SV where SV stands for SETVIEWS.
For example, a customized aplet called “Differentiation”
might call programs called DIFF.ME1, DIFF.ME2, and
DIFF.SV.
Example
This example aplet is designed to demonstrate the
process of customizing an aplet. The new aplet is based
on the Function aplet. Note: This aplet is not intended to
serve a serious use, merely to illustrate the process.
hp40g+.book Page 10 Friday, December 9, 2005 1:03 AM
Programming 21-11
Save the aplet 1. Open the Function aplet and save it as
“EXPERIMENT. The new aplet appears in the Aplet
library.
Select
Function
EXPERIMENT
2. Create a program
called EXP.ME1 with
contents as shown. This
program configures the
plot ranges, then runs a
program that allows
you to set the angle format.
3. Create a program
called EXP.ME2 with
contents as shown. This
program sets the
numeric view options
for the aplet, and runs
the program that you can use to configure the angle
mode.
4. Create a program
called EXP.ANG which
the previous two
programs call.
5. Create a program
called EXP.S which runs
when you start the
aplet, as shown. This
program sets the angle
mode to degrees, and
sets up the initial function that the aplet plots.
Configuring the
Setviews menu
option
programs
In this section we will begin by configuring the
VIEWS menu by using the SETVIEWS command. We
will then create the “helper” programs called by the
VIEWS menu which will do the actual work.
hp40g+.book Page 11 Friday, December 9, 2005 1:03 AM
21-12 Programming
6. Open the Program catalog and create a program
named “EXP.SV”. Include the following code in the
program.
Each entry line after the command SETVIEWS is a trio
that consists of a VIEWS menu text line (a space
indicates none), a program name, and a number that
defines the view to go to after the program has run its
course. All programs listed here will transfer with an
aplet when the aplet is transferred.
SETVIEWS ’ ; ; 18;
Sets the first menu option to be “Auto
scale. This is the fourth standard Function
aplet view menu option and the 18 “Auto
scale, specifies that it is to be included in
the new menu. The empty quotes will
ensure that the old name of “Auto scale
appears on the new menu. See
“SETVIEWS” on page 21-14.
My Entry1’;’EXP.ME1’;1;
Sets the second menu option. This option
runs program EXP.ME1, then returns to
view 1, Plot view.
My Entry2’;’EXP.ME2’;3;
Sets the third menu option. This option
runs the program EXP.ME2, then returns to
view 3, the NUM view.
;’ EXP.SV’;0;
This line specifies that the program to set
the View menu (this program) is
transferred with the aplet. The space
character between the first set of quotes in
the trio specifies that no menu option
appears for the entry. You do not need to
transfer this program with the aplet, but it
allows users to modify the aplet’s menu if
they want to.
hp40g+.book Page 12 Friday, December 9, 2005 1:03 AM
Programming 21-13
;’ EXP.ANG’;0;
The program EXP.ANG is a small routine
that is called by other programs that the
aplet uses. This entry specifies that the
program EXP.ANG is transferred when the
aplet is transferred, but the space in the
first quotes ensures that no entry appears
on the menu.
Start’;’EXP.S’;7:
This specifies the Start menu option. The
program that is associated with this entry,
EXP.S, runs automatically when you
start the aplet. Because this menu option
specifies view 7, the VIEWS menu opens
when you start the aplet.
You only need to run this program once to configure
your aplet’s VIEWS menu. Once the aplet’s VIEWS
menu is configured, it remains that way until you run
SETVIEWS again.
You do not need to include this program for your
aplet to work, but it is useful to specify that the
program is attached to the aplet, and transmitted
when the aplet is transmitted.
7. Return to the program
catalog. The programs
that you created should
appear as follows:
8. You must now the
program EXP.SV to execute the SETVIEWS command
and create the modified VIEWS menu. Check that the
name of the new aplet is highlighted in the Aplet
view.
9. You can now return to the Aplet library and press
to run your new aplet.
Programming commands
This section describes the commands for programming
with HP 40gs. You can enter these commands in your
program by typing them or by accessing them from the
Commands menu.
hp40g+.book Page 13 Friday, December 9, 2005 1:03 AM
21-14 Programming
Aplet commands
CHECK Checks (selects) the corresponding function in the current
aplet. For example, Check 3 would check F3 if the current
aplet is Function. Then a checkmark would appear next
to F3 in Symbolic view, F3 would be plotted in Plot view,
and evaluated in Numeric view.
CHECK n:
SELECT Selects the named aplet and makes it the current aplet.
Note: Quotes are needed if the name contains spaces or
other special characters.
SELECT apletname:
SETVIEWS The SETVIEWS command is used to define entries in the
VIEWS menu for aplets that you customize. See
“Customizing an aplet” on page 21-9 for an example of
using the SETVIEWS command.
When you use the SETVIEWS command, the aplet’s
standard VIEWS menu is deleted and the customized
menu is used in its place. You only need to apply the
command to an aplet once. The VIEWS menu changes
remain unless you apply the command again.
Typically, you develop a program that uses the
SETVIEWS command only. The command contains a trio
of arguments for each menu option to create, or program
to attach. Keep the following points in mind when using
this command:
The SETVIEWS command deletes an aplet’s standard
Views menu options. If you want to use any of the
standard options on your reconfigured VIEWS menu,
you must include them in the configuration.
When you invoke the SETVIEWS command, the
changes to an aplet’s VIEWS menu remain with the
aplet. You need to invoke the command on the aplet
again to change the VIEWS menu.
All the programs that are called from the VIEWS
menu are transferred when the aplet is transferred, for
example to another calculator or to a PC.
As part of the VIEWS menu configuration, you can
specify programs that you want transferred with the
aplet, but are not called as menu options. For
example, these can be sub-programs that menu
hp40g+.book Page 14 Friday, December 9, 2005 1:03 AM
Programming 21-15
options use, or the program that defines the aplet’s
VIEWS menu.
You can include a “Start” option in the VIEWS menu
to specify a program that you want to run
automatically when the aplet starts. This program
typically sets up the aplet’s initial configuration. The
START option on the menu is also useful for resetting
the aplet.
Command syntax
The syntax for the command is as follows:
SETVIEWS
"Prompt1";"ProgramName1";ViewNumber1;
"Prompt2";"ProgramName2";ViewNumber2:
(You can repeat as many Prompt/ProgramName/
ViewNumber trios of arguments as you like.)
Within each Prompt/ProgramName/ViewNumber trio,
you separate each item with a semi-colon.
Prompt
Prompt is the text that is displayed for the corresponding
entry in the Views menu. Enclose the prompt text in
double quotes.
Associating programs with your aplet
If Prompt consists of a single space, then no entry appears
in the view menu. The program specified in the
ProgramName item is associated with the aplet and
transferred whenever the aplet is transmitted. Typically,
you do this if you want to transfer the Setviews program
with the aplet, or you want to transfer a sub-program that
other menu programs use.
Auto-run programs
If the Prompt item is “Start”, then the ProgramName
program runs whenever you start the aplet. This is useful
for setting up a program to configure the aplet. Users can
select the Start item from the VIEWS menu to reset the
aplet if they change configurations.
You can also define a menu item called “Reset” which is
auto-run if the user chooses the button in the APLET
view.
hp40g+.book Page 15 Friday, December 9, 2005 1:03 AM
21-16 Programming
ProgramName
ProgramName is the name of the program that runs when
the corresponding menu entry is selected. All programs
that are identified in the aplet’s SETVIEWS command are
transferred when the aplet is transmitted.
ViewNumber
ViewNumber is the number of a view to start after the
program finishes running. For example, if you want the
menu option to display the Plot view when the associated
program finishes, you would specify 1 as the
ViewNumber value.
Including standard menu options
To include one of an aplet’s standard VIEWS menu
options in your customized menu, set up the arguments
trio as follows:
The first argument specifies the menu item name:
Leave the argument empty to use the standard
Views menu name for the item, or
Enter a menu item name to replace the standard
name.
The second argument specifies the program to run:
Leave the argument empty to run the standard
menu option.
Insert a program name to run the program before
the standard menu option is executed.
The third argument specifies the view and the menu
number for the item. Determine the menu number
from the View numbers table below.
Note: SETVIEWS with no arguments resets the views
to default of the base aplet.
hp40g+.book Page 16 Friday, December 9, 2005 1:03 AM
Programming 21-17
View numbers
The Function aplet views are numbered as follows:
View numbers from 15 on will vary according to the
parent aplet. The list shown above is for the Function
aplet. Whatever the normal VIEWS menu for the parent
aplet, the first entry will become number 15, the second
number 16 and so on.
UNCHECK Unchecks (unselects) the corresponding function in the
current aplet. For example, Uncheck 3 would uncheck F3
if the current aplet is Function.
UNCHECK n:
Branch commands
Branch commands let a program make a decision based
on the result of one or more tests. Unlike the other
programming commands, the branch commands work in
logical groups. Therefore, the commands are described
together rather than each independently.
IF...THEN...END Executes a sequence of commands in the true-clause only
if the test-clause evaluates to true. Its syntax is:
IF test-clause
THEN true-clause END
0
1
2
3
4
5
6
7
8
9
10
HOME
Plot
Symbolic
Numeric
Plot-Setup
Symbolic-Setup
Numeric-Setup
Views
Note
Sketch view
Aplet Catalog
11
12
13
14
15
16
17
18
19
20
21
List Catalog
Matrix Catalog
Notepad Catalog
Program Catalog
Plot-Detail
Plot-Table
Overlay Plot
Auto scale
Decimal
Integer
Trig
hp40g+.book Page 17 Friday, December 9, 2005 1:03 AM
21-18 Programming
Example
1
XA :
IF A==1
THEN MSGBOX " A EQUALS 1" :
END:
IF... THEN... ELSE...
END
Executes the true-clause sequence of commands if the test-
clause is true, or the false-clause sequence of commands
if the test-clause is false.
IF test-clause
THEN true-clause ELSE false-clause END
Example
1
XA :
IF A==1 THEN
MSGBOX "A EQUALS 1" :
ELSE
MSGBOX "A IS NOT EQUAL TO 1" :
A+1
XA :
END:
CASE...END Executes a series of test-clause commands that execute
the appropriate true-clause sequence of commands. Its
syntax is:
CASE
IF test-clause
1
THEN true-clause
1
END
IF test-clause
2
THEN true-clause
2
END
.
.
.
IF test-clause
n
THEN true-clause
n
END
END:
When CASE is executed, test-clause
1
is evaluated. If the
test is true, true-clause
1
is executed, and execution skips
to END. If test-clause
1
if false, execution proceeds to test-
clause
2
. Execution with the CASE structure continues until
a true-clause is executed (or until all the test-clauses
evaluate to false).
IFERR...
THEN...
ELSE…
END...
Many conditions are automatically recognized by the HP
40gs as error conditions and are automatically treated as
errors in programs.
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Programming 21-19
IFERR...THEN...ELSE...END allows a program to intercept
error conditions that otherwise would cause the program
to abort. Its syntax is:
IFERR trap-clause
THEN clause_1
ELSE clause_2
END :
Example
IFERR
60/X
X Y:
THEN
MSGBOX "Error: X is zero.":
ELSE
MSGBOX "Value is "Y:
END:
RUN Runs the named program. If your program name contains
special characters, such as a space, then you must
enclose the file name in double quotes (" ").
RUN "program name": or RUN programname:
STOP Stops the current program.
STOP:
Drawing commands
The drawing commands act on the display. The scale of
the display depends on the current aplet's Xmin, Xmax,
Ymin, and Ymax values. The following examples assume
the HP 40gs default settings with the Function aplet as the
current aplet.
ARC Draws a circular arc, of given radius, whose centre is at
(x,y) The arc is drawn from start_angle_measurement to
end_angle_measurement.
ARC x;y;radius;start_angle_measurement ;
end_angle_measurement:
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21-20 Programming
Example
ARC 0;0;2;0;2π:
FREEZE:
Draws a circle centered
at (0,0) of radius 2. The
FREEZE command
causes the circle to
remain displayed on the screen until you press a key.
BOX Draws a box with diagonally opposite corners (x1,y1) and
(x2,y2).
BOX x1;y1;x2;y2:
Example
BOX -1;-1;1;1:
FREEZE:
Draws a box, lower
corner at (–1,–1),
upper corner at (1,1)
ERASE Clears the display
ERASE:
FREEZE Halts the program, freezing the current display.
Execution resumes when any key is pressed.
LINE Draws a line from (x1, y1) to (x2, y2).
LINE x1;y1;x2;y2:
PIXOFF Turns off the pixel at the specified coordinates (x,y).
PIXOFF x;y:
PIXON Turns on the pixel at the specified coordinates (x,y).
PIXON x;y:
TLINE Toggles the pixels along the line from (x1, y1) to (x2, y2)
on and off. Any pixel that was turned off, is turned on;
any pixel that was turned on, is turned off. TLINE can be
used to erase a line.
TLINE x1;y1;x2;y2:
hp40g+.book Page 20 Friday, December 9, 2005 1:03 AM
Programming 21-21
Example
TLINE 0;0;3;3:
Erases previously drawn 45 degree line from (0,0) to
(3,3), or draws that line if it doesn’t already exist.
Graphic commands
The graphic commands use the graphics variables G0
through G9—or the Page variable from Sketch—as
graphicname arguments. The position argument takes the
form (x,y). Position coordinates depend on the current
aplet’s scale, which is specified by Xmin, Xmax, Ymin,
and Ymax. The upper left corner of the target graphic
(graphic2) is at (Xmin,Ymax).
You can capture the current display and store it in G0 by
simultaneously pressing + .
DISPLAY Stores the current display in graphicname.
DISPLAY graphicname:
DISPLAY Displays graphic from graphicname in the display.
DISPLAY graphicname:
GROB Creates a graphic from expression, using font_size, and
stores the resulting graphic in graphicname. Font sizes
are 1, 2, or 3. If the fontsize argument is 0, the HP 40gs
creates a graphic display like that created by the SHOW
operation.
GROB graphicname;expression; fontsize:
GROBNOT Replaces graphic in graphicname with bitwise-inverted
graphic.
GROBNOT graphicname:
GROBOR Using the logical OR, superimposes graphicname2 onto
graphicname1. The upper left corner of graphicname2 is
placed at position.
GROBOR graphicname1;(position);graphicname2:
where position is expressed in terms of the current axes
settings, not in terms of pixel postion.
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21-22 Programming
GROBXOR Using the logical XOR, superimposes graphicname2 onto
graphicname1. The upper left corner of graphicname2 is
placed at position.
GROBXOR
graphicname1;(position);graphicname2:
MAKEGROB Creates graphic with given width, height, and
hexadecimal data, and stores it in graphicname.
MAKEGROB graphicname;width;height;hexdata:
PLOT Stores the Plot view display as a graphic in graphicname.
PLOT graphicname:
PLOT and DISPLAY can be used to transfer a copy
of the current PLOT view into the sketch view of the aplet
for later use and editing.
Example
1
XPageNum:
PLOTPage:
DISPLAY Page:
FREEZE:
This program stores the current PLOT view to the first page
in the sketch view of the current aplet and then displays
the sketch as a graphic object until any key is pressed.
PLOT Puts graph from graphicname into the Plot view display.
PLOT graphicname:
REPLACE Replaces portion of graphic in graphicname1 with
graphicname2, starting at position. REPLACE also
works for lists and matrices.
REPLACE
graphicname1;(position);graphicname2:
SUB Extracts a portion of the named graphic (or list or matrix),
and stores it in a new variable, name. The portion is
specified by position and positions.
SUB name;graphicname;(position);(positions):
ZEROGROB Creates a blank graphic with given width and height,
and stores it in graphicname.
ZEROGROB graphicname;width;height:
hp40g+.book Page 22 Friday, December 9, 2005 1:03 AM
Programming 21-23
Loop commands
Loop hp allow a program to execute a routine repeatedly.
The HP 40gs has three loop structures. The example
programs below illustrate each of these structures
incrementing the variable A from 1 to 12.
DO…UNTIL …END Do ... Until ... End is a loop command that executes the
loop-clause repeatedly until test-clause returns a true
(nonzero) result. Because the test is executed after the
loop-clause, the loop-clause is always executed at least
once. Its syntax is:
DO loop-clause UNTIL test-clause END
1
X A:
DO
A + 1
X A:
DISP 3;A:
UNTIL A == 12 END:
WHILE…
REPEAT…
END
While ... Repeat ... End is a loop command that
repeatedly evaluates test-clause and executes loop-clause
sequence if the test is true. Because the test-clause is
executed before the loop-clause, the loop-clause is not
executed if the test is initially false. Its syntax is:
WHILE test-clause REPEAT loop-clause END
1
X A:
WHILE A < 12 REPEAT
A+1
X A:
DISP 3;A:
END:
FOR…TO…STEP
...END
FOR name=start-expression TO end-expression
[STEP increment]; loop-clause END
FOR A=1 TO 12 STEP 1;
DISP 3;A:
END:
Note that the STEP parameter is optional. If it is omitted,
a step value of 1 is assumed.
BREAK Terminates loop.
BREAK:
hp40g+.book Page 23 Friday, December 9, 2005 1:03 AM
21-24 Programming
Matrix commands
The matrix commands take variables M0–M9 as
arguments.
ADDCOL Add Column. Inserts values into a column before
column_number in the specified matrix. You enter the
values as a vector. The values must be separated by
commas and the number of values must be the same as
the number of rows in the matrix name.
ADDCOL
name;[value
1
,...,value
n
];column_number:
ADDROW Add Row. Inserts values into a row before row_number in
the specified matrix. You enter the values as a vector. The
values must be separated by commas and the number of
values must be the same as the number of columns in the
matrix name.
ADDROW name;[value
1
,..., value
n
];row_number:
DELCOL Delete Column. Deletes the specified column from the
specified matrix.
DELCOL name;column_number:
DELROW Delete Row. Deletes the specified row from the specified
matrix.
DELROW name;row_number:
EDITMAT Starts the Matrix Editor and displays the specified matrix.
If used in programming, returns to the program when user
presses .
EDITMAT name:
RANDMAT Creates random matrix with a specified number of rows
and columns and stores the result in name
(name must be M0...M9). The entries will be integers
ranging from –9 to 9.
RANDMAT name;rows;columns:
REDIM Redimensions the specified matrix or vector to size. For a
matrix, size is a list of two integers {n1,n2}. For a vector,
size is a list containing one integer {n}.
REDIM name;size:
hp40g+.book Page 24 Friday, December 9, 2005 1:03 AM
Programming 21-25
REPLACE Replaces portion of a matrix or vector stored in name with
an object starting at position start. start for a matrix is a
list containing two numbers; for a vector, it is a single
number. Replace also works with lists and graphics.
REPLACE name;start;object:
SCALE Multiplies the specified row_number of the specified
matrix by value.
SCALE name;value;rownumber:
SCALEADD Multiplies the row of the matrix name by value, then adds
this result to the second specified row.
SCALEADD name;value;row1;row2 :
SUB Extracts a sub-object—a portion of a list, matrix, or
graphic from object—and stores it into name. start and
end are each specified using a list with two numbers for
a matrix, a number for vector or lists, or an ordered pair,
(X,Y), for graphics.
SUB name;object;start;end:
SWAPCOL Swaps Columns. Exchanges column1 and column2 of the
specified matrix.
SWAPCOL name;column1;column2:
SWAPROW Swap Rows. Exchanges row1 and row2 in the specified
matrix.
SWAPROW name;row1;row2:
Print commands
These commands print to an HP infrared printer, for
example the HP 82240B printer.
PRDISPLAY Prints the contents of the display.
PRDISPLAY:
PRHISTORY Prints all objects in the history.
PRHISTORY:
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21-26 Programming
PRVAR Prints name and contents of variablename.
PRVAR variablename:
You can also use the PRVAR command to print the
contents of a program or a note.
PRVAR programname;PROG:
PRVAR notename;NOTE:
Prompt commands
BEEP Beeps at the frequency and for the time you specify.
BEEP frequency;seconds:
CHOOSE Creates a choose box, which is a box containing a list of
options from which the user chooses one. Each option is
numbered, 1 through n. The result of the choose
command is to store the number of the option chosen in a
variable. The syntax is:
CHOOSE variable_name; title; option
1
; option
2
;
...option
n
:
where variable_name is the name of a variable for
storing a default option number, title is the text displayed
in the title bar of the choose box, and option
1
...option
n
are the options listed in the choose box.
By pre-storing a value into variable_name you can
specify the default option number, as shown in the
example below.
Example
3
X A:CHOOSE A;
"COMIC STRIPS";
"DILBERT";
"CALVIN&HOBBES";
"BLONDIE":
CLRVAR Clears the specified variable. The syntax is:
CLRVAR variable :
hp40g+.book Page 26 Friday, December 9, 2005 1:03 AM
Programming 21-27
Example
If you have stored
{1,2,3,4} in variable L1,
entering CLVAR L1
will clear L1.
DISP Displays textitem in a row of the display at the
line_number. A text item consists of any number of
expressions and quoted strings of text. The expressions
are evaluated and turned into strings. Lines are numbered
from the top of the screen, 1 being the top and 7 being
the bottom.
DISP line_number;textitem:
Example
DISP 3;"A is" 2+2
Result: A is 4
(displayed on line 3)
DISPXY Displays object at position (x_pos, y_pos) in size font. The
syntax is:
DISPXY x_pos;y_pos;font;object:
The value of object can be a text string, a variable, or a
combination of both. x_pos and y_pos are relative to the
current settings of Xmin, Xmax, Ymin and Ymax (which
you set in the PLOT SETUP view). The value of font is either
1 (small) or 2 (large).
Example
DISPXY
–3.5;1.5;2;"HELLO
WORLD":
DISPTIME Displays the current date and time.
DISPTIME
To set the date and time, simply store the correct settings
in the date and time variables. Use the following formats:
M.DDYYYY for the date and H.MMSS for the time.
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21-28 Programming
Examples
5.152000
X DATE(sets the date to May 15, 2000).
10.1500
X TIME (sets the time to 10:15 am).
EDITMAT Matrix Editor. Opens the Matrix editor for the specified
matrix. Returns to the program when user presses
EDITMAT matrixname:
The EDITMAT command can also be used to create
matrices.
1. Press
CMDS
2. Press M 1, and then press .
The Matrix catalog opens with M1 available for
editing.
EDITMAT matrixname is an alternative to opening the
matrix editor with matrixname. It can be used in a
program to enter a matrix.
FREEZE This command prevents the display from being updated
after the program runs. This allows you to view the
graphics created by the program. Cancel FREEZE by
pressing any key.
FREEZE:
GETKEY Waits for a key, then stores the keycode rc.p in name,
where r is row number, c is column number, and p is key-
plane number. The key-planes numbers are: 1 for
unshifted; 2 for shifted; 4 for alpha-shifted; and 5 for both
alpha-shifted and shifted.
GETKEY name:
INPUT Creates an input form with a title bar and one field. The
field has a label and a default value. There is text help at
the bottom of the form. The user enters a value and
presses the menu key. The value that the user enters
is stored in the variable name. The title, label, and help
items are text strings and need to be enclosed in double
quotes.
Use
CHARS to type the quote marks " ".
INPUT name;title,label;help;default:
hp40g+.book Page 28 Friday, December 9, 2005 1:03 AM
Programming 21-29
Example
INPUT R; "Circular Area";
"Radius";
"Enter Number";1:
MSGBOX Displays a message box containing textitem. A text item
consists of any number of expressions and quoted strings
of text. The expressions are evaluated and turned into
strings of text.
For example, "AREA IS:" 2+2 becomes AREA IS: 4.
Use CHARS to type the quote marks " ".
MSGBOX textitem:
Example
1
X A:
MSGBOX "AREA IS: "π*A^2:
You can also use the NoteText variable to provide text
arguments. This can be used to insert line breaks. For
example, press
NOTE and type AREA IS .
The position line
MSGBOX NoteText " " π*A^2:
will display the same message box as the previous
example.
PROMPT Displays an input box with name as the title, and prompts
for a value for name. name can be a variable such as
A…Z, θ, L1…L9, C1…C9 or Z1…Z9..
PROMPT name:
WAIT Halts program execution for the specified number of
seconds.
WAIT seconds:
Stat-One and Stat-Two commands
The following commands are used for analyzing one-
variable and two-variable statistical data.
hp40g+.book Page 29 Friday, December 9, 2005 1:03 AM
21-30 Programming
Stat-One commands
DO1VSTATS Calculates STATS using datasetname and stores the
results in the corresponding variables: NΣ, TotΣ, MeanΣ,
PVarΣ, SVarΣ, PSDev, SSDev, MinΣ, Q1, Median, Q3,
and MaxΣ. Datasetname can be H1, H2, ..., or H5.
Datasetname must include at least two data points.
DO1VSTATS datasetname:
SETFREQ Sets datasetname frequency according to column or
value. Datasetname can be H1, H2,..., or H5, column
can be C0–C9 and value can be any positive integer.
SETFREQ datasetname;column:
or
SETFREQ definition;value:
SETSAMPLE Sets datasetname sample according to column.
Datasetname can be H1–H5, and column can be
CO–C9.
SETSAMPLE datasetname;column:
Stat-Two commands
DO2VSTATS Calculates STATS using datasetname and stores the
results in corresponding variables: MeanX, ΣX, ΣX2,
MeanY, ΣY, ΣY2, ΣXY, Corr, PCov, SCov, and RELERR.
Datasetname can be SI, S2,..., or S5. Datasetname must
include at least two pairs of data points.
DO2VSTATS datasetname:
SETDEPEND Sets datasetname dependent column. Datasetname can
be S1, S2, …, or S5 and column can be C0–C9.
SETDEPEND datasetname;column:
SETINDEP Sets datasetname independent column. Datasetname can
be S1, S2,…, or S5 and column can be C0–C9.
SETINDEP datasetname;column:
hp40g+.book Page 30 Friday, December 9, 2005 1:03 AM
Programming 21-31
Storing and retrieving variables in programs
The HP 40gs has both Home variables and Aplet
variables. Home variables are used for real numbers,
complex numbers, graphics, lists, and matrices. Home
variables keep the same values in HOME and in aplets.
Aplet variables are those whose values depend on the
current aplet. The aplet variables are used in
programming to emulate the definitions and settings you
make when working with aplets interactively.
You use the Variable menu ( ) to retrieve either
Home variables or aplet variables. See “The VARS menu”
on page 17-4. Not all variables are available in every
aplet. S1fit–S5fit, for example, are only available in the
Statistics aplet. Under each variable name is a list of the
aplets where the variable can be used.
Plot-view variables
Area
Function
Contains the last value found by the Area function in Plot-
FCN menu.
Axes
All Aplets
Turns axes on or off.
From Plot Setup, check (or uncheck)
AXES.
or
In a program, type:
1
X Axes—to turn axes on (default).
0 X Axes—to turn axes off.
Connect
Function
Parametric
Polar
Solve
Statistics
Draws lines between successively plotted points.
From Plot Setup, check (or uncheck)
CONNECT.
or
In a program, type
1
X Connectto connect plotted points (default,
except in Statistics where the default is off).
0
X Connectnot to connect plotted points.
hp40g+.book Page 31 Friday, December 9, 2005 1:03 AM
21-32 Programming
Coord
Function
Parametric
Polar
Sequence
Solve
Statistics
Turns the coordinate-display mode in Plot view on or off.
From Plot view, use the Menu mean key to toggle
coordinate display on an off.
In a program, type
1
X Coord—to turn coordinate display on (default).
0
X Coord—to turn coordinate display off.
Extremum
Function
Contains the last value found by the Extremum operation
in the Plot-FCN menu.
FastRes
Function
Solve
Toggles resolution between plotting in every other column
(faster), or plotting in every column (more detail).
From Plot Setup, choose Faster or More Detail.
or
In a program, type
1
X FastRes—for faster.
0 X FastRes—for more detail (default).
Grid
All Aplets
Turns the background grid in Plot view on or off. From Plot
setup, check (or uncheck)
GRID.
or
In a program, type
1
X Grid to turn the grid on.
0 X Grid to turn the grid off (default).
Hmin/Hmax
Statistics
Defines minimum and maximum values for histogram
bars.
From Plot Setup for one-variable statistics, set values for
HRNG.
or
In a program, type
X Hmin
X Hmax
where
n
1
n
2
n
2
n
1
>
hp40g+.book Page 32 Friday, December 9, 2005 1:03 AM
Programming 21-33
Hwidth
Statistics
Sets the width of histogram bars.
From Plot Setup in 1VAR stats set a value for Hwidth
or
In a program, type
n
X Hwidth
Indep
All Aplets
Defines the value of the independent variable used in
tracing mode.
In a program, type
n
X Indep
InvCross
All Aplets
Toggles between solid crosshairs or inverted crosshairs.
(Inverted is useful if the background is solid).
From Plot Setup, check (or uncheck) InvCross
or
In a program, type:
1
X InvCross—to invert the crosshairs.
0 X InvCross —for solid crosshairs (default).
Isect
Function
Contains the last value found by the Intersection function
in the Plot-FCN menu.
Labels
All Aplets
Draws labels in Plot view showing X and Y ranges.
From Plot Setup, check (or uncheck)
Labels
or
In a program, type
1
XLabels—to turn labels on.
0
XLabels—to turn labels off (default).
hp40g+.book Page 33 Friday, December 9, 2005 1:03 AM
21-34 Programming
Nmin / Nmax
Sequence
Defines the minimum and maximum independent variable
values. Appears as the NRNG fields in the Plot Setup input
form.
From Plot Setup, enter values for NRNG.
or
In a program, type
XNmin
XNmax
where
Recenter
All Aplets
Recenters at the crosshairs locations when zooming.
From Plot-Zoom-Set Factors, check (or uncheck)
Recenter
or
In a program, type
1
X Recenter— to turn recenter on (default).
0
X Recenter—to turn recenter off.
Root
Function
Contains the last value found by the Root function in the
Plot-FCN menu.
S1mark–S5mark
Statistics
Sets the mark to use for scatter plots.
From Plot Setup for two-variable statistics, S1mark-
S5mark, then choose a mark.
or
In a program, type
n
X S1mark
where n is 1,2,3,...5
SeqPlot
Sequence
Enables you to choose types of sequence plot: Stairstep
or Cobweb.
From Plot Setup, select SeqPlot, then choose
Stairstep or Cobweb.
or
In a program, type
1
X SeqPlot—for Stairstep.
2
X SeqPlot—for Cobweb.
n
1
n
2
n
2
n
1
>
hp40g+.book Page 34 Friday, December 9, 2005 1:03 AM
Programming 21-35
Simult
Function
Parametric
Polar
Sequence
Enables you to choose between simultaneous and
sequential graphing of all selected expressions.
From Plot Setup, check (or uncheck) _SIMULT
or
In a program, type
1
X Simult—for simultaneous graphing (default).
0
X Simult—for sequential graphing.
Slope
Function
Contains the last value found by the Slope function in the
Plot-FCN menu.
StatPlot
Statistics
Enables you to choose types of 1-variable statistics plot
between Histogram or Box-and-Whisker.
From Plot Setup, select StatPlot, then choose
Histogram or BoxWhisker.
or
In a program, type
1
X StatPlot—for Histogram.
2 X StatPlot—for Box-and-Whisker.
Umin/Umax
Polar
Sets the minimum and maximum independent values.
Appears as the URNG field in the Plot Setup input form.
From the Plot Setup input form, enter values for URNG.
or
In a program, type
X Umin
X Umax
where
Ustep
Polar
Sets the step size for an independent variable.
From the Plot Setup input form, enter values for USTEP.
or
In a program, type
n
X Ustep
where
n
1
n
2
n
2
n
1
>
n 0>
hp40g+.book Page 35 Friday, December 9, 2005 1:03 AM
21-36 Programming
Tmin / Tmax
Parametric
Sets the minimum and maximum independent variable
values. Appears as the TRNG field in the Plot Setup input
form.
From Plot Setup, enter values for TRNG.
or
In a program, type
X Tmin
X Tmax
where
Tracing
All Aplets
Turns the tracing mode on or off in Plot view.
In a program, type
1
X Tracing—to turn Tracing mode on (default).
0
X Tracing—to turn Tracing mode off.
Tstep
Parametric
Sets the step size for the independent variable.
From the Plot Setup input form, enter values for TSTEP.
or
In a program, type
n
X Tstep
where
Xcross
All Aplets
Sets the horizontal coordinate of the crosshairs. Only
works with TRACE off.
In a program, type
n
X Xcross
Ycross
All Aplets
Sets the vertical coordinate of the crosshairs. Only works
with TRACE off.
In a program, type
n X Ycross
n
1
n
2
n
2
n
1
>
n 0>
hp40g+.book Page 36 Friday, December 9, 2005 1:03 AM
Programming 21-37
Xtick
AAll Aplets
Sets the distance between tick marks for the horizontal
axis.
From the Plot Setup input form, enter a value for Xtick.
or
In a program, type
n
X Xtick where
Ytick
All Aplets
Sets the distance between tick marks for the vertical axis.
From the Plot Setup input form, enter a value for Ytick.
or
In a program, type
n
X Ytick where
Xmin / Xmax
All Aplets
Sets the minimum and maximum horizontal values of the
plot screen. Appears as the XRNG fields (horizontal
range) in the Plot Setup input form.
From Plot Setup, enter values for XRNG.
or
In a program, type
X Xmin
X Xmax
where
Ymin / Ymax
All Aplets
Sets the minimum and maximum vertical values of the plot
screen. Appears as the YRNG fields (vertical range) in the
Plot Setup input form.
From Plot Setup, enter the values for YRNG.
or
In a program, type
X Ymin
X Ymax
where
n 0>
n 0>
n
1
n
2
n
2
n
1
>
n
1
n
2
n
2
n
1
>
hp40g+.book Page 37 Friday, December 9, 2005 1:03 AM
21-38 Programming
Xzoom
All Aplets
Sets the horizontal zoom factor.
From Plot-ZOOM-Set Factors, enter the value for XZOOM.
or
In a program, type
n
X XZOOM
where
The default value is 4.
Yzoom
All Aplets
Sets the vertical zoom factor.
From Plot-ZOOM-Set Factors, enter the value for YZOOM.
or
In a program, type
n
X YZOOM
The default value is 4.
Symbolic-view variables
Angle
All Aplets
Sets the angle mode.
From Symbolic Setup, choose Degrees, Radians, or
Grads for angle measure.
or
In a program, type
1
X Angle —for Degrees.
2
X Angle —for Radians.
3
X Angle—for Grads.
F1...F9, F0
Function
Can contain any expression. Independent variable is X.
Example
'SIN(X)'
X F1(X)
You must put single quotes around an expression to keep
it from being evaluated before it is stored. Use
CHARS to type the single quote mark.
n 0>
hp40g+.book Page 38 Friday, December 9, 2005 1:03 AM
Programming 21-39
X1, Y1...X9,Y9
X0,Y0
Parametric
Can contain any expression. Independent variable is T.
Example
'SIN(4*T)'
X Y1(T):'2*SIN(6*T)' X
X1(T)
R1...R9, R0
Polar
Can contain any expression. Independent variable is θ.
Example
'2*SIN(2*θ)'
X R1(θ)
U1...U9, U0
Sequence
Can contain any expression. Independent variable is N.
Example
RECURSE (U,U(N-1)*N,1,2)
X U1(N)
E1...E9, E0
Solve
Can contain any equation or expression. Independent
variable is selected by highlighting it in Numeric View.
Example
'X+Y*X-2=Y'
X E1
S1fit...S5fit
Statistics
Sets the type of fit to be used by the FIT operation in
drawing the regression line.
From Symbolic Setup view, specify the fit in the field for
S1FIT, S2FIT, etc.
or
In a program, store one of the following constant numbers
or names into a variable S1fit, S2fit, etc.
1 Linear
2 LogFit
3 ExpFit
4 Power
5 QuadFit
6 Cubic
7 Logist
8 ExptFit
9 TrigFit
10 User
hp40g+.book Page 39 Friday, December 9, 2005 1:03 AM
21-40 Programming
Example
Cubic
X S2fit
or
6
X S2fit
Numeric-view variables
The following aplet variables control the Numeric view.
The value of the variable applies to the current aplet only.
C1...C9, C0
Statistics
C0 through C9, for columns of data. Can contain lists.
Enter data in the Numeric view
or
In a program, type
LIST
XCn
where n = 0, 1, 2, 3 ... 9
Digits
All Aplets
Number of decimal places to use for Number format in
the HOME view and for labeling axes in the Plot view.
From the Modes view, enter a value in the second field of
Number Format.
or
In a program, type
n
X Digits
where
Format
All Aplets
Defines the number display format to use for numeric
format on the HOME view and for labeling axes in the
Plot view.
From the Modes view, choose Standard, Fixed,
Scientific, Engineering, Fraction or Mixed
Fraction in the Number Format field.
or
In a program, store the constant number (or its name) into
the variable Format.
0 n 11<<
hp40g+.book Page 40 Friday, December 9, 2005 1:03 AM
Programming 21-41
1 Standard
2 Fixed
3 Sci
4 Eng
5 Fraction
6 MixFraction
Note: if Fraction or Mixed Fraction is chosen, the
setting will be disregarded when labeling axes in the Plot
view. A setting of Scientific will be used instead.
Example
Scientific
X Format
or
3
X Format
NumCol
All Aplets except
Statistics aplet
Sets the column to be highlighted in Numeric view.
In a program, type
n X NumCol
where n can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.
NumFont
Function
Parametric
Polar
Sequence
Statistics
Enables you to choose the font size in Numeric view.
Does not appear in the Num Setup input form.
Corresponds to the key in Numeric view.
In a program, type
0
X NumFont for small (default).
1
X NumFont for big.
NumIndep
Function
Parametric
Polar
Sequence
Specifies the list of independent values to be used by
Build Your Own Table.
In a program, type
LIST
X NumIndep
NumRow
All Aplets except
Statistics aplet
Sets the row to be highlighted in Numeric view.
In a program, type
n
X NumRow
where
n 0>
hp40g+.book Page 41 Friday, December 9, 2005 1:03 AM
21-42 Programming
NumStart
Function
Parametric
Polar
Sequence
Sets the starting value for a table in Numeric view.
From Num Setup, enter a value for NUMSTART.
or
In a program, type
n
X NumStart
NumStep
Function
Parametric
Polar
Sequence
Sets the step size (increment value) for an independent
variable in Numeric view.
From Num Setup, enter a value for NUMSTEP.
or
In a program, type
n
X NumStep
where
NumType
Function
Parametric
Polar
Sequence
Sets the table format.
From Num Setup, choose Automatic or Build Your
Own.
or
In a program, type
0
X NumType for Build Your Own.
1 X NumType for Automatic (default).
NumZoom
Function
Parametric
Polar
Sequence
Sets the zoom factor in the Numeric view.
From Num Setup, type in a value for NUMZOOM.
or
In a program, type
n
X NumZoom
where
StatMode
Statistics
Enables you to choose between 1-variable and 2-variable
statistics in the Statistics aplet. Does not appear in the Plot
Setup input form. Corresponds to the and
menu keys in Numeric View.
In a program, store the constant name (or its number) into
the variable StatMode. 1VAR =1, 2VAR=2.
n 0>
n 0>
hp40g+.book Page 42 Friday, December 9, 2005 1:03 AM
Programming 21-43
Example
1VAR
X StatMode
or
1
X StatMode
Note variables
The following aplet variable is available in Note view.
NoteText
All Aplets
Use NoteText to recall text previously entered in Note
view.
Sketch variables
The following aplet variables are available in Sketch
view.
Page
All Aplets
Sets a page in a sketch set. The graphics can be viewed
one at a time using the and keys.
The Page variable refers to the currently displayed page
of a sketch set.
In a program, type
graphicname
X Page
PageNum
All Aplets
Sets a number for referring to a particular page of the
sketch set (in Sketch view).
In a program, type the page that is shown when
SKETCH is pressed.
n
X PageNum
hp40g+.book Page 43 Friday, December 9, 2005 1:03 AM
hp40g+.book Page 44 Friday, December 9, 2005 1:03 AM
Extending aplets 22-1
22
Extending aplets
Aplets are the application environments where you
explore different classes of mathematical operations.
You can extend the capability of the HP 40gs in the
following ways:
Create new aplets, based on existing aplets, with
specific configurations such as angle measure,
graphical or tabular settings, and annotations.
Transmit aplets between HP 40gs calculators via a
serial or USB cable.
Download e-lessons (teaching aplets) from
Hewlett-Packard’s Calculator web site.
Program new aplets. See chapter 21,
“Programming”, for further details.
Creating new aplets based on existing aplets
You can create a new aplet based on an existing aplet.
To create a new aplet, save an existing aplet under a new
name, then modify the aplet to add the configurations
and the functionality that you want.
Information that defines an aplet is saved automatically
as it is entered into the calculator.
To keep as much memory available for storage as
possible, delete any aplets you no longer need.
Example This example demonstrates how to create a new aplet by
saving a copy of the built-in Solve aplet. The new aplet is
saved under the name “TRIANGLES” and contains the
formulas commonly used in calculations involving
right-angled triangles.
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
22-2 Extending aplets
1. Open the Solve aplet and save it under the new
name.
Solve
|
T R I A N G L E S
2. Enter the four formulas:
θ
O
H
θ
A
H
θ
OA
AB
C
3. Decide whether you want the aplet to operate in
Degrees, Radians, or Grads.
MODES
Degrees
4. View the Aplet Library. The “TRIANGLES” aplet is
listed in the Aplet Library.
The Solve aplet can now
be reset and used for
other problems.
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
Extending aplets 22-3
Using a customized aplet
To use the “Triangles” aplet, simply select the appropriate
formula, change to the Numeric view and solve for the
missing variable.
Find the length of a ladder leaning against a vertical wall
if it forms an angle of 35
o
with the horizontal and
extends 5 metres up the wall.
1. Select the aplet.
TRIANGLES
2. Choose the sine formula
in E1.
3. Change to the Numeric
view and enter the
known values.
35
5
4. Solve for the missing
value.
The length of the ladder
is approximately 8.72 metres
Resetting an aplet
Resetting an aplet clears all data and resets all default
settings.
To reset an aplet, open the Library, select the aplet and
press .
You can only reset an aplet that is based on a built-in
aplet if the programmer who created it has provided a
Reset option.
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
22-4 Extending aplets
Annotating an aplet with notes
The Note view ( NOTE) attaches a note to the current
aplet. See Chapter 20, “Notes and sketches”.
Annotating an aplet with sketches
The Sketch view ( SKETCH) attaches a picture to the
current aplet. See chapter 20, “Notes and sketches”.
HINT
Notes and sketches that you attach to an aplet become
part of the aplet. When you transfer the aplet to another
calculator, the associated note and sketch are transferred
as well.
Downloading e-lessons from the web
In addition to the standard aplets that come with the
calculator, you can download aplets from the world wide
web. For example, Hewlett-Packard’s Calculators web
site contains aplets that demonstrate certain mathematical
concepts. Note that you need the Graphing Calculator
Connectivity Kit in order to load aplets from a PC.
Hewlett-Packard’s Calculators web site can be found at:
http://www.hp.com/calculators
Sending and receiving aplets
A convenient way to distribute or share problems in class
and to turn in homework is to transmit (copy) aplets
directly from one HP 40gs to another. This can take place
via a suitable cable. ( You can use a serial cable with a
4-pin mini-USB connector, which plugs into the RS232
port on the calculator. The serial cable is available as a
separate accessory.)
You can also send aplets to, and receive aplets from, a
PC. This requires special software running on the PC (such
as the PC Connectivity Kit). A USB cable with a 5-pin mini-
USB connector is provided with the hp40gs for
connecting with a PC. It plugs into the USB port on the
calculator.
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
Extending aplets 22-5
To transmit
an aplet
1. Connect the PC or aplet disk drive to the calculator by
an appropriate cable.
2. Sending calculator: Open the Library, highlight the
aplet to send, and press .
The
SEND TO menu appears with the following
options:
HP39/40 (USB) = to send via the USB port
HP39/40 (SER) = to send via the RS232 serial port
USB DISK DRIVE = to send to a disk drive via the USB
port
SER. DISK DRIVE = to send to a disk drive via the
RS232 serial port
Note: choose a disk drive option if you are using
the hp40gs connectivity kit to transfer the aplet.
Highlight your selection and press .
If transmitting to a disk drive, you have the
options of sending to the current (default)
directory or to another directory.
3. Receiving calculator: Open the aplet library and
press .
The
RECEIVE FROM menu appears with the following
options:
HP39/40 (USB) = to receive via the USB port
HP39/40 (SER) = to receive via the RS232 serial port
USB DISK DRIVE = to receive from a disk drive via the
USB port
SER. DISK DRIVE = to receive from a disk drive via the
RS232 serial port
Note: choose a disk drive option if you are using
the hp40gs connectivity kit to transfer the aplet.
Highlight your selection and press .
The Transmit annunciator— —is displayed until
transmission is complete.
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
22-6 Extending aplets
If you are using the PC Connectivity Kit to download
aplets from a PC, you will see a list of aplets in the PC’s
current directory. Check as many items as you would like
to receive.
Sorting items in the aplet library menu list
Once you have entered information into an aplet, you
have defined a new version of an aplet. The information
is automatically saved under the current aplet name, such
as “Function.” To create additional aplets of the same
type, you must give the current aplet a new name.
The advantage of storing an aplet is to allow you to keep
a copy of a working environment for later use.
The aplet library is where you go to manage your aplets.
Press . Highlight (using the arrow keys) the name
of the aplet you want to act on.
To sort the
aplet list
In the aplet library, press . Select the sorting scheme
and press .
Chronologically produces a chronological order
based on the date an aplet was last used. (The last-
used aplet appears first, and so on.)
Alphabetically produces an alphabetical order
by aplet name.
To delete an
aplet
You cannot delete a built-in aplet. You can only clear its
data and reset its default settings.
To delete a customized aplet, open the aplet library,
highlight the aplet to be deleted, and press . To
delete all custom aplets, press
CLEAR.
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
R-1
R
Reference information
Glossary
aplet A small application, limited to one
topic. The built-in aplet types are
Function, Parametric, Polar,
Sequence, Solve, Statistics,
Inference, Finance, Trig Explorer,
Quad Explorer, Linear Explorer and
Triangle Solve. An aplet can be filled
with the data and solutions for a
specific problem. It is reusable (like a
program, but easier to use) and it
records all your settings and
definitions.
command An operation for use in programs.
Commands can store results in
variables, but do not display results.
Arguments are separated by semi-
colons, such as DISP
expression;line#.
expression A number, variable, or algebraic
expression (numbers plus functions)
that produces a value.
function An operation, possibly with
arguments, that returns a result. It
does not store results in variables. The
arguments must be enclosed in
parentheses and separated with
commas (or periods in Comma
mode), such as
CROSS(matrix1,matrix2).
HOME The basic starting point of the
calculator. Go to HOME to do
calculations.
Library For aplet management: to start, save,
reset, send and receive aplets.
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
R-2
list A set of values separated by commas
(periods if the Decimal Mark mode is
set to Comma) and enclosed in
braces. Lists are commonly used to
enter statistical data and to evaluate
a function with multiple values.
Created and manipulated by the List
editor and catalog.
matrix A two-dimensional array of values
separated by commas (periods if the
Decimal Mark mode is set to Comma)
and enclosed in nested brackets.
Created and manipulated by the
Matrix catalog and editor. Vectors
are also handled by the Matrix
catalog and editor.
menu A choice of options given in the
display. It can appear as a list or as
a set of menu-key labels across the
bottom of the display.
menu keys The top row of keys. Their operations
depend on the current context. The
labels along the bottom of the display
show the current meanings.
note Text that you write in the Notepad or
in the Note view for a specific aplet.
program A reusable set of instructions that you
record using the Program editor.
sketch A drawing that you make in the
Sketch view for a specific aplet.
variable The name of a number, list, matrix,
note, or graphic that is stored in
memory. Use to store and use
to retrieve.
vector A one-dimensional array of values
separated by commas (periods if the
Decimal Mark mode is set to Comma)
and enclosed in single brackets.
Created and manipulated by the
Matrix catalog and editor.
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
R-3
Resetting the HP 40gs
If the calculator “locks up” and seems to be stuck, you
must reset it. This is much like resetting a PC. It cancels
certain operations, restores certain conditions, and clears
temporary memory locations. However, it does not clear
stored data (variables, aplet databases, programs) unless
you use the procedure, “To erase all memory and reset
defaults”.
To reset using
the keyboard
Press and hold the key and the third menu key
simultaneously, then release them.
If the calculator does not respond to the above key
sequence, then:
1. Turn the calculator over and locate the small hole in
the back of the calculator.
2. Insert the end of a straightened metal paper clip into
the hole as far as it will go. Hold it there for 1
second, then remove it.
3. Press If necessary, press and the first and
last menu keys simultaneously. (Note: This will erase
your calculator memory.)
To erase all memory and reset defaults
If the calculator does not respond to the above resetting
procedures, you might need to restart it by erasing all of
memory. You will lose everything you have stored. All
factory-default settings are restored.
1. Press and hold the key, the first menu key, and
the last menu key simultaneously.
2. Release all keys in the reverse order.
Note: To cancel this process, release only the top-row
keys, then press the third menu key.
views The possible contexts for an aplet:
Plot, Plot Setup, Numeric, Numeric
Setup, Symbolic, Symbolic Setup,
Sketch, Note, and special views like
split screens.
ReferenceInfo.fm Page 3 Friday, December 16, 2005 11:26 AM
R-4
If the calculator does not turn on
If the HP 40gs does not turn on follow the steps below
until the calculator turns on. You may find that the
calculator turns on before you have completed the
procedure. If the calculator still does not turn on, please
contact Customer Support for further information.
1. Press and hold the key for 10 seconds.
2. Press and hold the key and the third menu key
simultaneously. Release the third menu key, then
release the key.
3. Press and hold the key, the first menu key, and
the sixth menu key simultaneously. Release the sixth
menu key, then release the first menu key, and then
release the key.
4. Locate the small hole in the back of the calculator.
Insert the end of a straightened metal paper clip into
the hole as far as it will go. Hold it there for 1
second, then remove it. Press the key.
5. Remove the batteries (see “Batteries” on page R-4),
press and hold the key for 10 seconds, and
then put the batteries back in. Press the key.
Operating details
Operating temperature: 0° to 45°C (32° to 113°F).
Storage temperature: –20° to 65°C (– 4° to 149°F).
Operating and storage humidity: 90% relative
humidity at 40°C (104°F) maximum. Avoid getting the
calculator wet.
Battery operates at 6.0V dc, 80mA maximum.
Batteries
The calculator uses 4 AAA(LR03) batteries as main power
and a CR2032 lithium battery for memory backup.
Before using the calculator, please install the batteries
according to the following procedure.
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
R-5
To install the main
batteries
a. Slide up the battery compartment cover as illustrated.
b. Insert 4 new AAA (LR03) batteries into the main
compartment. Make sure each battery is inserted in the
indicated direction.
To install the
backup battery
a. Press down the holder. Push the plate to the shown
direction and lift it.
b. Insert a new CR2032 lithium battery. Make sure its
positive (+) side is facing up.
c. Replace the plate and push it to the original place.
After installing the batteries, press to turn the power
on.
Warning: It is recommended that you replace this battery
every 5 years. When the low battery icon is displayed,
you need to replace the batteries as soon as possible.
However, avoid removing the backup battery and main
batteries at the same time to avoid data lost.
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
R-6
Variables
Home variables
The home variables are:
Category Available name
Complex Z1...Z9, Z0
Graphic G1...G9, G0
Library Function
Parametric
Polar
Sequence
Solve
Statistics
User-named
List L1...L9, L0
Matrix M1...M9, M0
Modes Ans
Date
HAngle
HDigits
HFormat
Ierr
Time
Notepad User-named
Program Editline
User-named
Real A...Z, θ
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
R-7
Function aplet variables
The function aplet variables are:
Category Available name
Plot Axes
Connect
Coord
FastRes
Grid
Indep
InvCross
Labels
Recenter
Simult
Tracing
Xcross
Ycross
Xtick
Ytick
Xmin
Xmax
Ymin
Ymax
Xzoom
Yxoom
Plot-FCN Area
Extremum
Isect
Root
Slope
Symbolic Angle
F1
F2
F3
F4
F5
F6
F7
F8
F9
F0
Numeric Digits
Format
NumCol
NumFont
NumIndep
NumRow
NumStart
NumStep
NumType
NumZoom
Note NoteText
Sketch Page PageNum
hp40g+.book Page 7 Friday, December 9, 2005 1:03 AM
R-8
Parametric aplet variables
The parametric aplet variables are:
Category Available name
Plot Axes
Connect
Coord
Grid
Indep
InvCross
Labels
Recenter
Simult
Tmin
Tmax
Tracing
Tstep
Xcross
Ycross
Xtick
Ytick
Xmin
Xmax
Ymin
Ymax
Xzoom
Yzoom
Symbolic Angle
X1
Y1
X2
Y2
X3
Y3
X4
Y4
X5
Y5
X6
Y6
X7
Y7
X8
Y8
X9
Y9
X0
Y0
Numeric Digits
Format
NumCol
NumFont
NumIndep
NumRow
NumStart
NumStep
NumType
NumZoom
Note NoteText
Sketch Page PageNum
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
R-9
Polar aplet variables
The polar aplet variables are:
Category Available names
Plot Axes
Connect
Coord
Grid
Indep
InvCross
Labels
Recenter
Simult
Umin
Umax
θstep
Tracing
Xcross
Ycross
Xtick
Ytick
Xmin
Xmax
Ymin
Ymax
Xzoom
Yxoom
Symbolic Angle
R1
R2
R3
R4
R5
R6
R7
R8
R9
R0
Numeric Digits
Format
NumCol
NumFont
NumIndep
NumRow
NumStart
NumStep
NumType
NumZoom
Note NoteText
Sketch Page PageNum
hp40g+.book Page 9 Friday, December 9, 2005 1:03 AM
R-10
Sequence aplet variables
The sequence aplet variables are:
Category Available name
Plot Axes
Coord
Grid
Indep
InvCross
Labels
Nmin
Nmax
Recenter
SeqPlot
Simult
Tracing
Xcross
Ycross
Xtick
Ytick
Xmin
Xmax
Ymin
Ymax
Xzoom
Yzoom
Symbolic Angle
U1
U2
U3
U4
U5
U6
U7
U8
U9
U0
Numeric Digits
Format
NumCol
NumFont
NumIndep
NumRow
NumStart
NumStep
NumType
NumZoom
Note NoteText
Sketch Page PageNum
hp40g+.book Page 10 Friday, December 9, 2005 1:03 AM
R-11
Solve aplet variables
The solve aplet variables are:
Category Available name
Plot Axes
Connect
Coord
FastRes
Grid
Indep
InvCross
Labels
Recenter
Tracing
Xcross
Ycross
Xtick
Ytick
Xmin
Xmax
Ymin
Ymax
Xzoom
Yxoom
Symbolic Angle
E1
E2
E3
E4
E5
E6
E7
E8
E9
E0
Numeric Digits
Format
NumCol
NumRow
Note NoteText
Sketch Page PageNum
hp40g+.book Page 11 Friday, December 9, 2005 1:03 AM
R-12
Statistics aplet variables
The statistics aplet variables are:
Category Available name
Plot Axes
Connect
Coord
Grid
Hmin
Hmax
Hwidth
Indep
InvCross
Labels
Recenter
S1mark
S2mark
S3mark
S4mark
S5mark
StatPlot
Tracing
Xcross
Ycross
Xtick
Ytick
Xmin
Xmax
Ymin
Ymax
Xzoom
Yxoom
Symbolic Angle
S1fit
S2fit
S3fit
S4fit
S5fit
Numeric C0,...C9
Digits
Format
NumCol
NumFont
NumRow
StatMode
Stat-One MaxΣ
MeanΣ
Median
MinΣ
NΣ
Q1
Q3
PSDev
SSDev
PVarΣ
SVarΣ
TotΣ
Stat-Two Corr
Cov
Fit
MeanX
MeanY
RelErr
ΣX
ΣX2
ΣXY
ΣY
ΣY2
Note NoteText
Sketch Page PageNum
hp40g+.book Page 12 Friday, December 9, 2005 1:03 AM
R-13
MATH menu categories
Math functions
The math functions are:
Category Available name
Calculus
TAYLOR
Complex ARG
CONJ
IM
RE
Constant e
i
MAXREAL
MINREAL
π
Hyperb. ACOSH
ASINH
ATANH
COSH
SINH
TANH
ALOG
EXP
EXPM1
LNP1
List CONCAT
ΔLIST
MAKELIST
πLIST
POS
REVERSE
SIZE
ΣLIST
SORT
Loop ITERATE
RECURSE
Σ
hp40g+.book Page 13 Friday, December 9, 2005 1:03 AM
R-14
Matrix COLNORM
COND
CROSS
DET
DOT
EIGENVAL
EIGENVV
IDENMAT
INVERSE
LQ
LSQ
LU
MAKEMAT
QR
RANK
ROWNORM
RREF
SCHUR
SIZE
SPECNORM
SPECRAD
SVD
SVL
TRACE
TRN
Polynom. POLYCOEF
POLYEVAL
POLYFORM
POLYROOT
Prob. COMB
!
PERM
RANDOM
UTPC
UTPF
UTPN
UTPT
Real CEILING
DEGRAD
FLOOR
FNROOT
FRAC
HMS
HMS
INT
MANT
MAX
MIN
MOD
%
%CHANGE
%TOTAL
RADDEG
ROUND
SIGN
TRUNCATE
XPON
Stat-Two PREDX
PREDY
Symbolic =
ISOLATE
LINEAR?
QUAD
QUOTE
|
Category Available name (Continued)
hp40g+.book Page 14 Friday, December 9, 2005 1:03 AM
R-15
Program constants
The program constants are:
Tests
<
= =
>
AND
IFTE
NOT
OR
XOR
Trig ACOT
ACSC
ASEC
COT
CSC
SEC
Category Available name (Continued)
Category Available name
Angle Degrees
Grads
Radians
Format Standard
Fixed
Sci
Eng
Fraction
SeqPlot Cobweb
Stairstep
S1...5fit Linear
LogFit
ExpFit
Power
Trigonometric
QuadFit
Cubic
Logist
User
Exponent
StatMode Stat1Var
Stat2Var
StatPlot Hist
BoxW
hp40g+.book Page 15 Friday, December 9, 2005 1:03 AM
R-16
Physical Constants
The physical constants are:
Category Available Name
Chemist Avogadro (Avagadro’s Number,
NA)
Boltz. (Boltmann, k)
mol. vo... (molar volume, Vm)
univ gas (universal gas, R)
std temp (standard temperature,
St dT)
std pres (standard pressure,
St dP)
Phyics StefBolt (Stefan-Boltzmann, σ)
•light s... (speed of light, c)
permitti (permittivity, ε0)
permeab (permeability, μ0)
acce gr... (acceleration of
gravity, g)
gravita... (gravitation, G)
Quantum Plank’s (Plank’s constant, h)
Dirac’s (Dirac’s, hbar)
e charge (electronic charge, q)
e mass (electron mass, me)
q/me ra... (q/me ratio, qme)
proton m (proton mass, mp)
mp/me r... (mp/me ratio,
mpme)
fine str (fine structure, α)
mag flux (magnetic flux, φ)
Faraday (Faraday, F)
Rydberg (Rydberg, )
Bohr rad (Bohr radius, a0)
Bohr mag (Bohr magneton, μB)
nuc. mag (nuclear magneton,
μN)
photon...
(photon wavelength,
λ)
photon... (photon frequency,
f0)
Compt w... (Compton
wavelength, λc)
R
hp40g+.book Page 16 Friday, December 9, 2005 1:03 AM
R-17
CAS functions
CAS functions are:
Category Function
Algebra COLLECT
DEF
EXPAND
FACTOR
PARTFRAC
QUOTE
STORE
|
SUBST
TEXPAND
UNASSIGN
Complex i
ABS
ARG
CONJ
DROITE
IM
RE
SIGN
Constant e
i
π
Diff & Int DERIV
DERVX
DIVPC
FOURIER
IBP
INTVX
lim
PREVAL
RISCH
SERIES
TABVAR
TAYLOR0
TRUNC
Hyperb. ACOSH
ASINH
ATANH
COSH
SINH
TANH
Integer DIVIS
EULER
FACTOR
GCD
IDIV2
IEGCD
IQUOT
IREMAINDER
ISPRIME?
LCM
MOD
NEXTPRIME
PREVPRIME
Modular ADDTMOD
DIVMOD
EXPANDMOD
FACTORMOD
GCDMOD
INVMOD
MODSTO
MULTMOD
POWMOD
SUBTMOD
hp40g+.book Page 17 Friday, December 9, 2005 1:03 AM
R-18
Polynom. EGCD
FACTOR
GCD
HERMITE
LCM
LEGENDRE
PARTFRAC
PROPFRAC
PTAYL
QUOT
REMAINDER
TCHEBYCHEFF
Real CEILING
FLOOR
FRAC
INT
MAX
MIN
Rewrite DISTRIB
EPSX0
EXPLN
EXP2POW
FDISTRIB
LIN
LNCOLLECT
POWEXPAND
SINCOS
SIMPLIFY
XNUM
XQ
Solve DESOLVE
ISOLATE
LDEC
LINSOLVE
SOLVE
SOLVEVX
Tests ASSUME
UNASSUME
>
<
= =
AND
OR
NOT
IFTE
Trig ACOS2S
ASIN2C
ASIN2T
ATAN2S
HALFTAN
SINCOS
TAN2CS2
TAN2SC
TAN2SC2
TCOLLECT
TEXPAMD
TLIN
TRIG
TRIGCOS
TRIGSIN
TRIGTAN
Category Function (Continued)
hp40g+.book Page 18 Friday, December 9, 2005 1:03 AM
R-19
Program commands
The program commands are:
Category Command
Aplet CHECK
SELECT
SETVIEWS
UNCHECK
Branch IF
THEN
ELSE
END
CASE
IFERR
RUN
STOP
Drawing ARC
BOX
ERASE
FREEZE
LINE
PIXOFF
PIXON
TLINE
Graphic DISPLAY
DISPLAY
GROB
GROBNOT
GROBOR
GROBXOR
MAKEGROB
PLOT
PLOT
REPLACE
SUB
ZEROGROB
Loop FOR
=
TO
STEP
END
DO
UNTIL
END
WHILE
REPEAT
END
BREAK
Matrix ADDCOL
ADDROW
DELCOL
DELROW
EDITMAT
RANDMAT
REDIM
REPLACE
SCALE
SCALEADD
SUB
SWAPCOL
SWAPROW
Print PRDISPLAY
PRHISTORY
PRVAR
Prompt BEEP
CHOOSE
CLRVAR
DISP
DISPXY
DISPTIME
EDITMAT
FREEZE
GETKEY
INPUT
MSGBOX
PROMPT
WAIT
Stat-One DO1VSTATS
RANDSEED
SETFREQ
SETSAMPLE
hp40g+.book Page 19 Friday, December 9, 2005 1:03 AM
Status messages
Stat-Two DO2VSTATS
SETDEPEND
SETINDEP
Category Command (Continued)
Message Meaning
Bad Argument
Type
Incorrect input for this
operation.
Bad Argument
Value
The value is out of range for this
operation.
Infinite Result Math exception, such as 1/0.
Insufficient
Memory
You must recover some memory
to continue operation. Delete
one or more matrices, lists,
notes, or programs (using
catalogs), or custom (not built-
in) aplets (using
MEMORY).
Insufficient
Statistics Data
Not enough data points for the
calculation. For two-variable
statistics there must be two
columns of data, and each
column must have at least four
numbers.
Invalid Dimension Array argument had wrong
dimensions.
Invalid Statistics
Data
Need two columns with equal
numbers of data values.
hp40g+.book Page 20 Friday, December 9, 2005 1:03 AM
R-21
Invalid Syntax The function or command you
entered does not include the
proper arguments or order of
arguments. The delimiters
(parentheses, commas,
periods, and semi-colons) must
also be correct. Look up the
function name in the index to
find its proper syntax.
Name Conflict The | (where) function
attempted to assign a value to
the variable of integration or
summation index.
No Equations
Checked
You must enter and check an
equation (Symbolic view)
before evaluating this function.
(OFF SCREEN) Function value, root, extremum,
or intersection is not visible in
the current screen.
Receive Error Problem with data reception
from another calculator. Re-
send the data.
Too Few
Arguments
The command requires more
arguments than you supplied.
Undefined Name The global variable named
does not exist.
Undefined Result The calculation has a
mathematically undefined result
(such as 0/0).
Out of Memory You must recover a lot of
memory to continue operation.
Delete one or more matrices,
lists, notes, or programs (using
catalogs), or custom (not built-
in) aplets (using
MEMORY).
Message Meaning (Continued)
hp40g+.book Page 21 Friday, December 9, 2005 1:03 AM
hp40g+.book Page 22 Friday, December 9, 2005 1:03 AM
W-1
Limited Warranty
HP 40gs Graphing Calculator; Warranty period: 12
months
1. HP warrants to you, the end-user customer, that HP
hardware, accessories and supplies will be free from
defects in materials and workmanship after the date
of purchase, for the period specified above. If HP
receives notice of such defects during the warranty
period, HP will, at its option, either repair or replace
products which prove to be defective. Replacement
products may be either new or like-new.
2. HP warrants to you that HP software will not fail to
execute its programming instructions after the date of
purchase, for the period specified above, due to
defects in material and workmanship when properly
installed and used. If HP receives notice of such
defects during the warranty period, HP will replace
software media which does not execute its
programming instructions due to such defects.
3. HP does not warrant that the operation of HP
products will be uninterrupted or error free. If HP is
unable, within a reasonable time, to repair or replace
any product to a condition as warranted, you will be
entitled to a refund of the purchase price upon
prompt return of the product with proof of purchase.
4. HP products may contain remanufactured parts
equivalent to new in performance or may have been
subject to incidental use.
5. Warranty does not apply to defects resulting from (a)
improper or inadequate maintenance or calibration,
(b) software, interfacing, parts or supplies not
supplied by HP, (c) unauthorized modification or
misuse, (d) operation outside of the published
environmental specifications for the product, or (e)
improper site preparation or maintenance.
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
W-2
6. HP MAKES NO OTHER EXPRESS WARRANTY OR
CONDITION WHETHER WRITTEN OR ORAL. TO
THE EXTENT ALLOWED BY LOCAL LAW, ANY
IMPLIED WARRANTY OR CONDITION OF
MERCHANTABILITY, SATISFACTORY QUALITY, OR
FITNESS FOR A PARTICULAR PURPOSE IS LIMITED
TO THE DURATION OF THE EXPRESS WARRANTY
SET FORTH ABOVE. Some countries, states or
provinces do not allow limitations on the duration of
an implied warranty, so the above limitation or
exclusion might not apply to you. This warranty gives
you specific legal rights and you might also have
other rights that vary from country to country, state to
state, or province to province.
7. TO THE EXTENT ALLOWED BY LOCAL LAW, THE
REMEDIES IN THIS WARRANTY STATEMENT ARE
YOUR SOLE AND EXCLUSIVE REMEDIES. EXCEPT AS
INDICATED ABOVE, IN NO EVENT WILL HP OR ITS
SUPPLIERS BE LIABLE FOR LOSS OF DATA OR FOR
DIRECT, SPECIAL, INCIDENTAL, CONSEQUENTIAL
(INCLUDING LOST PROFIT OR DATA), OR OTHER
DAMAGE, WHETHER BASED IN CONTRACT, TORT,
OR OTHERWISE. Some countries, States or provinces
do not allow the exclusion or limitation of incidental
or consequential damages, so the above limitation or
exclusion may not apply to you.
8. The only warranties for HP products and services are
set forth in the express warranty statements
accompanying such products and services . HP shall
not be liable for technical or editorial errors or
omissions contained herein.
FOR CONSUMER TRANSACTIONS IN AUSTRALIA AND
NEW ZEALAND: THE WARRANTY TERMS CONTAINED
IN THIS STATEMENT, EXCEPT TO THE EXTENT
LAWFULLY PERMITTED, DO NOT EXCLUDE, RESTRICT
OR MODIFY AND ARE IN ADDITION TO THE
MANDATORY STATUTORY RIGHTS APPLICABLE TO THE
SALE OF THIS PRODUCT TO YOU.
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
W-3
Service
Europe Country : Telephone numbers
Austria +43-1-3602771203
Belgium +32-2-7126219
Denmark +45-8-2332844
Eastern Europe
countries
+420-5-41422523
Finland +35-89640009
France +33-1-49939006
Germany +49-69-95307103
Greece +420-5-41422523
Holland +31-2-06545301
Italy +39-02-75419782
Norway +47-63849309
Portugal +351-229570200
Spain +34-915-642095
Sweden +46-851992065
Switzerland +41-1-4395358
(German)
+41-22-8278780
(French)
+39-02-75419782
(Italian)
Turkey +420-5-41422523
UK +44-207-4580161
Czech Republic +420-5-41422523
South Africa +27-11-2376200
Luxembourg +32-2-7126219
Other European
countries
+420-5-41422523
Asia Pacific
Country : Telephone numbers
Australia +61-3-9841-5211
Singapore +61-3-9841-5211
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
W-4
Please logon to http://www.hp.com for the latest service
and support information.h
L.America
Country: Telephone numbers
Argentina 0-810-555-5520
Brazil Sao Paulo 3747-7799;
ROTC 0-800-157751
Mexico Mx City 5258-9922;
ROTC 01-800-472-6684
Venezuela 0800-4746-8368
Chile 800-360999
Columbia 9-800-114726
Peru 0-800-10111
Central
America &
Caribbean
1-800-711-2884
Guatemala 1-800-999-5105
Puerto Rico 1-877-232-0589
Costa Rica 0-800-011-0524
N.America
Country : Telephone numbers
U.S. 1800-HP INVENT
Canada (905) 206-4663 or
800- HP INVENT
ROTC = Rest of the country
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
W-5
Regulatory Notices
Federal Commu-
nications
Commission
Notice
This equipment has been tested and found to comply with
the limits for a Class B digital device, pursuant to Part 15
of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference in a
residential installation. This equipment generates, uses,
and can radiate radio frequency energy and, if not
installed and used in accordance with the instructions,
may cause harmful interference to radio communications.
However, there is no guarantee that interference will not
occur in a particular installation. If this equipment does
cause harmful interference to radio or television
reception, which can be determined by turning the
equipment off and on, the user is encouraged to try to
correct the interference by one or more of the following
measures:
Reorient or relocate the receiving antenna.
Increase the separation between the equipment and
the receiver.
Connect the equipment into an outlet on a circuit
different from that to which the receiver is connected.
Consult the dealer or an experienced radio or
television technician for help.
Modifications The FCC requires the user to be notified that any changes
or modifications made to this device that are not
expressly approved by Hewlett-Packard Company may
void the user's authority to operate the equipment.
Cables Connections to this device must be made with shielded
cables with metallic RFI/EMI connector hoods to maintain
compliance with FCC rules and regulations.
Declaration of
Conformity for
Products
Marked with
FCC Logo,
United States
Only
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions: (1)
this device may not cause harmful interference, and (2)
this device must accept any interference received,
including interference that may cause undesired
operation.
For questions regarding your product, contact:
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
W-6
Hewlett-Packard Company
P. O. Box 692000, Mail Stop 530113
Houston, Texas 77269-2000
Or, call
1-800-474-6836
For questions regarding this FCC declaration, contact:
Hewlett-Packard Company
P. O. Box 692000, Mail Stop 510101
Houston, Texas 77269-2000
Or, call
1-281-514-3333
To identify this product, refer to the part, series, or model
number found on the product.
Canadian
Notice
This Class B digital apparatus meets all requirements of
the Canadian Interference-Causing Equipment
Regulations.
Avis Canadien Cet appareil numérique de la classe B respecte toutes les
exigences du Règlement sur le matériel brouilleur du
Canada.
European Union
Regulatory
Notice
This product complies with the following EU Directives:
Low Voltage Directive 73/23/EEC
EMC Directive 89/336/EEC
Compliance with these directives implies conformity to
applicable harmonized European standards (European
Norms) which are listed on the EU Declaration of
Conformity issued by Hewlett-Packard for this product or
product family.
This compliance is indicated by the following conformity
marking placed on the product:
This marking is valid for non-Telecom products
and EU harmonized Telecom products (e.g. Bluetooth).
xxxx
*
This marking is valid for EU non-harmonized Telecom products .
*Notified body number (used only if applicable - refer to the product label)
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
W-7
Japanese Notice の装置は 情報処理装置等電波障害自主規制協議会
(VCCI) の基準 B 情報技術装置 の装
置は、 家庭環使用す 目的 すが
装置が 受信機近接 使用
受信障害 す。
扱い説明書に従 い取扱い い。
Korean Notice
Disposal of Waste
Equipment by Users
in Private
Household in the
European Union
This symbol on the product or on its
packaging indicates that this product
must not be disposed of with your other
household waste. Instead, it is your
responsibility to dispose of your waste
equipment by handing it over to a
designated collection point for the
recycling of waste electrical and
electronic equipment. The separate collection and
recycling of your waste equipment at the time of disposal
will help to conserve natural resources and ensure that it
is recycled in a manner that protects human health and
the environment. For more information about where you
can drop off your waste equipment for recycling, please
contact your local city office, your household waste
disposal service or the shop where you purchased the
product.
hp40g+.book Page 7 Friday, December 9, 2005 1:03 AM
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
I-1
Index
A
ABCUV 14-62
ABS
14-45
absolute value
13-6
ACOS2S
14-38
add
13-4
ADDTMOD
14-51
ALGB menu
14-10
algebraic entry
1-19
alpha characters
typing
1-6
alphabetical sorting
22-6
angle measure 1-10
in statistics 10-12
setting
1-11
animation
20-5
creating 20-5
annunciators
1-3
Ans (last answer) 1-24
antiderivative 14-68, 14-69
antilogarithm
13-4, 13-10
aplet
attaching notes 22-4
clearing
22-3
copying
22-4
definition of
R-1
deleting
22-6
Function
13-21
Inference
11-1
key
1-4
library
22-6
Linear Solver
8-1
opening
1-16
Parametric
4-1
Polar
5-1
receiving
22-5
resetting
22-3
sending
22-4, 22-5
Sketch view
20-1
Solve
7-1
sorting
22-6
statistics
10-1
transmitting
22-5
Triangle Solver
9-1
aplet commands
CHECK
21-14
SELECT
21-14
SETVIEWS
21-17
UNCHECK
21-17
aplet variables
definition
17-1, 17-8
in Plot view
21-31
new
17-1
aplet views
canceling operations in
1-1
changing
1-19
note
1-18
Numeric view
1-17
Plot view
1-16
sketch
1-18
split-screen
1-17
Symbolic view
1-16
approximation
14-32
arc cosecant
13-20
arc cosine 13-5
arc cotangent 13-20
arc secant
13-20
arc sine 13-4
arc tangent 13-5
area
graphical
3-10
interactive
3-10
variable
21-31
ARG
13-7
arguments
with matrices
18-10
ASIN2C
14-39
ASIN2T
14-39
ASSUME
14-61
ATAN2S
14-39
attaching
a note to an aplet
20-1
a sketch to an aplet
20-3
auto scale
2-14
axes
plotting
2-7
variable
21-31
B
bad argument R-20
hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM
I-2
bad guesses error message 7-7
batteries
R-4
Bernoulli’s number 14-65
box-and-whisker plot 10-16
branch commands
CASE...END
21-18
IF...THEN...ELSE...END
21-18
IFERR...THEN...ELSE
21-18
branch structures
21-17
build your own table 2-19
C
calculus
operations 13-7
CAS
14-1, 15-1
configuration 15-3
help
15-4
history
14-8
in HOME
14-7
list of functions
14-9, R-17
modes
14-5, 15-3
online help
14-8
variables
14-4
catalogs
1-30
CFG 15-3
Chinese remainders
14-62, 14-65
CHINREM 14-62
chronological sorting 22-6
circle drawing
20-4
clearing
aplet
22-3
characters
1-22
display
1-22
display history
1-25
edit line
1-22
lists
19-6
plot
2-7
cobweb graph
6-1
coefficients
polynomial
13-11
COLLECT
14-10
columns
changing position
21-25
combinations
13-12
commands
aplet 21-14
branch
21-17
definition of
R-1
drawing
21-19
graphic
21-21
loop
21-23
print
21-25
program
21-4, R-19
stat-one
21-29
stat-two
21-30
with matrices
18-10
complex number functions
13-6,
13-17
conjugate
13-7
imaginary part
13-7
real part
13-8
complex numbers
1-29
entering 1-29
math functions
13-7
storing
1-29
computer algebra system See CAS
confidence intervals
11-15
CONJ
13-7
conjugate 13-7
connecting
data points
10-19
variable
21-31
via serial cable
22-5
via USB cable
22-5
connectivity kit
22-4
constant? error message 7-7
constants
e
13-8
i
13-8
maximum real number
13-8
minimum real number
13-8
physical
1-8, 13-25, R-16
program
R-15, R-16
contrast
decreasing display
1-2
increasing display
1-2
conversions
13-8
coordinate display
2-9
copying
display 1-22
graphics
20-6
notes
20-8
programs
21-8
correlation
coefficient
10-17
CORR
10-17
statistical
10-15
cosecant
13-20
hp40g+.book Page 2 Friday, December 9, 2005 1:03 AM
I-3
cosine 13-4
inverse hyperbolic
13-9
cotangent
13-20
covariance
statistical
10-15
creating
aplet
22-1
lists
19-1
matrices
18-2
notes in Notepad
20-6
programs
21-4
sketches
20-3
critical value(s) displayed
11-4
cross product
vector
18-11
curve fitting
10-12, 10-17
CYCLOTOMIC
14-63
D
data set definition 10-8
date, setting
21-27
debugging programs 21-7
decimal
changing format
1-10
scaling
2-14, 2-15
decreasing display contrast
1-2
DEF
14-10
definite integral 13-6
deleting
aplet
22-6
lists
19-6
matrices
18-4
programs
21-9
statistical data
10-11
delimiters, programming
21-1
DERIV
14-16
derivative
14-16
derivatives
definition of 13-6
in Function aplet
13-22
in Home
13-21
DERVX
14-16
DESOLVE
14-33
determinant
square matrix 18-11
DIFF menu
14-16
differential equations 14-33, 14-35,
14-57
differentiation 13-6, 14-33
digamma function
14-67, 14-68
display 21-21
adjusting contrast 1-2
annunciator line
1-2
capture
21-21
clearing
1-2
date and time
21-27
element
18-5
elements
19-4
engineering
1-10
fixed
1-10
fraction
1-10
history
1-22
line
1-23
matrices
18-5
parts of
1-2
printing contents
21-25
rescaling
2-13
scientific
1-10
scrolling through history
1-25
soft key labels
1-2
standard
1-10
DISTRIB
14-28
distributivity 14-12, 14-28, 14-30
divide
13-4
DIVIS 14-47
DIVMOD 14-52
DIVPC
14-17
drawing
circles
20-4
keys
20-4
lines and boxes
20-3
drawing commands
ARC
21-19
BOX
21-20
ERASE
21-20
FREEZE
21-20
LINE
21-20
PIXOFF
21-20
PIXON
21-20
TLINE
21-20
DROITE
14-45
E
e 13-8
edit line 1-2
editing
matrices
18-4
hp40g+.book Page 3 Friday, December 9, 2005 1:03 AM
I-4
notes 20-2
programs
21-5
Editline
Program catalog
21-2
editors
1-30
EGCD 14-55
eigenvalues 18-11
eigenvectors
18-11
element
storing 18-6
E-lessons
1-12
engineering number format 1-11
EPSX0
14-29
equals
for equations 13-17
logical test
13-19
Equation Writer
14-2, 15-1, 16-1
selecting terms 15-5
equations
solving
7-1
erasing a line in Sketch view
21-20
error messages
bad guesses
7-7
constant?
7-7
Euclidean division
14-48, 14-49
EULER 14-47
exclusive OR
13-20
exiting views 1-19
EXP2HYP 14-63
EXP2POW
14-29
EXPAND 14-12
EXPANDMOD
14-52
expansion
14-25, 14-27
EXPLN 14-29
exponent
fit
10-13
minus 1
13-10
of value
13-17
raising to
13-5
exponentials
14-30, 14-63
expression
defining
2-1, R-1
entering in HOME
1-19
evaluating in aplets
2-3
literal
13-18
plot
3-3
extended greatest common divisor
14-55
extremum 3-10
F
FACTOR 14-12, 14-47, 14-56
factorial 13-13
factorization
14-12
FACTORMOD 14-53
FastRes variable 21-32
FDISTRIB
14-30
fit
a curve to 2VAR data 10-17
choosing
10-12
defining your own
10-13
fixed number format
1-10
font size
change
3-8, 15-2, 20-5
forecasting
10-20
FOURIER 14-17
fraction number format 1-11
full-precision display
1-10
function
analyze graph with FCN tools
3-4
definition
2-2, R-1
entering
1-19
gamma
13-13
intersection point
3-5
math menu
R-13, R-17
slope
3-5
syntax
13-2
tracing
2-8
Function aplet
2-20, 3-1
function variables
area
21-31
axes
21-31
connect
21-31
fastres
21-32
grid
21-32
in menu map
R-7
indep
21-33
isect
21-33
labels
21-34
Recenter
21-34
root
21-34
ycross
21-37
G
GAMMA 14-64
GCD 14-47, 14-56
GCDMOD
14-53
hp40g+.book Page 4 Friday, December 9, 2005 1:03 AM
I-5
glossary R-1
graph
analyzing statistical data in
10-19
auto scale
2-14
box-and-whisker
10-16
capture current display
21-21
cobweb
6-1
comparing
2-5
connected points
10-17
defining the independent variable
21-36
drawing axes
2-7
expressions
3-3
grid points
2-7
histogram
10-15
in Solve aplet
7-7
one-variable statistics
10-18
overlaying
2-15
scatter
10-15, 10-17
split-screen view
2-14
splitting into plot and close-up
2-13
splitting into plot and table
2-13
stairsteps
6-1
statistical data
10-15
t values
2-6
tickmarks
2-6
tracing
2-8
two-variable statistics
10-18
Graphic commands
GROB
21-21
DISPLAY
21-21
GROBNOT
21-21
GROBOR
21-21
GROBXOR
21-22
MAKEGROB
21-22
PLOT
21-22
REPLACE
21-22
SUB
21-22
ZEROGROB
21-22
graphics
copying
20-6
copying into Sketch view
20-6
storing and recalling
20-6, 21-21
greatest common divisor
14-56
H
HALFTAN 14-40
HERMITE
14-56
histogram 10-15
adjusting 10-16
range
10-18
setting min/max values for bars
21-32
width
10-18
history
1-2, 14-8, 21-25
Home 1-1
calculating in 1-19
display
1-2
evaluating expressions
2-4
reusing lines
1-23
variables
17-1, 17-7, R-6
home
14-7
horizontal zoom 21-38
hyperbolic
maths functions
13-10
hyperbolic trigonometry
ACOSH
13-9
ALOG
13-10
ASINH
13-9
ATANH
13-9
COSH
13-10
EXP
13-10
EXPM1
13-10
LNP1
13-10
SINH
13-10
TANH
13-10
hypothesis
alternative
11-2
inference tests
11-8
null
11-2
tests
11-2
I
i 13-8, 14-45
IABCUV
14-64
IBERNOULLI
14-65
IBP 14-18
ICHINREM
14-65
IDIV2
14-48
IEGCD 14-48
ILAP 14-65
IM
13-7
implied multiplication 1-20
importing
graphics
20-6
notes
20-8
increasing display contrast
1-2
indefinite integral
hp40g+.book Page 5 Friday, December 9, 2005 1:03 AM
I-6
using symbolic variables 13-23
independent values
adding to table
2-19
independent variable
defined for Tracing mode
21-33
inference
confidence intervals
11-15
hypothesis tests
11-8
One-Proportion Z-Interval
11-17
One-Sample Z-Interval
11-15
One-Sample Z-Test
11-8
Two-Proportion Z-Interval
11-17
Two-Proportion Z-Test
11-11
Two-Sample T-Interval
11-19
Two-Sample Z-Interval
11-16
infinite result
R-20
initial guess
7-5
input forms
resetting default values 1-9
setting Modes
1-11
insufficient memory
R-20
insufficient statistics data R-20
integer rank
matrix
18-12
integer scaling
2-14, 2-15
integral
definite 13-6
indefinite
13-23
integration
13-6, 14-18, 14-24
interpreting
intermediate guesses
7-7
intersection
3-11
INTVX
14-19
invalid
dimension
R-20
statistics data
R-20
syntax
R-21
inverse hyperbolic cosine
13-9
inverse hyperbolic functions
13-10
inverse hyperbolic sine
13-9
inverse hyperbolic tangent 13-9
inverse Laplace transform 14-66
inverting matrices
18-8
INVMOD 14-53
IQUOT 14-49
IREMAINDER
14-49
isect variable 21-33
ISOLATE
14-34
ISPRIME?
14-50
K
keyboard
editing keys 1-5
entry keys
1-5
inactive keys
1-8
list keys
19-2
math functions
1-7
menu keys
1-4
Notepad keys
20-8
shifted keystrokes
1-6
L
labeling
axes 2-7
parts of a sketch
20-5
LAP
14-67
Laplace transform 14-65
Laplace transform, inverse 14-66
LCM
14-50, 14-57
LDEC 14-35
least common multiple
14-50, 14-57
LEGENDRE 14-57
letters, typing 1-6
library, managing aplets in
22-6
lim 14-21
limits 14-21
LIN
14-30
linear fit 10-13
Linear Solver aplet
8-1
linear systems
14-35
linearize 14-30, 14-43
LINSOLVE
14-35
list
arithmetic with
19-7
calculate sequence of elements
19-8
calculating product of
19-8
composed from differences
19-7
concatenating
19-7
counting elements in
19-9
creating
19-1, 19-3, 19-4, 19-5
deleting
19-6
deleting list items
19-3
displaying
19-4
displaying list elements
19-4
editing
19-3
hp40g+.book Page 6 Friday, December 9, 2005 1:03 AM
I-7
finding statistical values in list ele-
ments
19-9
generate a series
19-8
list function syntax
19-6
list variables
19-1
returning position of element in
19-8
reversing order in
19-8
sending and receiving
19-6
sorting elements
19-9
storing elements
19-1, 19-4, 19-5
storing one element
19-6
LNCOLLECT
14-31
logarithm
13-4
logarithmic
fit 10-13
functions
13-4
logarithms
14-31
logical operators
AND 13-19
equals (logical test)
13-19
greater than
13-19
greater than or equal to
13-19
IFTE
13-19
less than
13-19
less than or equal to
13-19
NOT
13-19
not equal to
13-19
OR
13-19
XOR
13-20
logistic fit
10-13
loop commands
BREAK
21-23
DO...UNTIL...END
21-23
FOR I=
21-23
WHILE...REPEAT...END
21-23
loop functions
ITERATE
13-10
RECURSE
13-11
summation
13-11
low battery
1-1
lowercase letters 1-6
M
mantissa 13-15
math functions
complex number 13-7
hyperbolic
13-10
in menu map
R-13, R-17
keyboard
13-3
logical operators
13-19
menu
1-7
polynomial
13-11
probability
13-12
real-number
13-14
symbolic
13-17
trigonometry
13-20
MATH menu
13-1
math operations 1-19
enclosing arguments
1-21
in scientific notation
1-20
negative numbers in
1-20
matrices
adding rows
21-24
addition and subtraction
18-6
arguments
18-10
arithmetic operations in
18-6
assembly from vectors
18-1
changing row position
21-25
column norm
18-10
comma
19-7
commands
18-10
condition number
18-11
create identity
18-13
creating
18-3
creating in Home
18-5
deleting
18-4
deleting columns
21-24
deleting rows
21-24
determinant
18-11
display eigenvalues
18-11
displaying
18-5
displaying matrix elements
18-5
dividing by a square matrix
18-8
dot product
18-11
editing
18-4
extracting a portion
21-25
finding the trace of a square ma-
trix 18-13
inverting
18-8
matrix calculations
18-1
multiplying and dividing by scalar
18-7
multiplying by vector
18-7
multiplying row by value and add-
ing result to second row
21-25
multiplying row number by value
21-25
negating elements
18-8
opening Matrix Editor
21-28
raised to a power
18-7
hp40g+.book Page 7 Friday, December 9, 2005 1:03 AM
I-8
redimension 21-24
replacing portion of matrix or vec-
tor
21-25
sending or receiving
18-4
singular value decomposition
18-13
singular values
18-13
size
18-12
spectral norm
18-13
spectral radius
18-13
start Matrix Editor
21-24
storing elements
18-3, 18-5
storing matrix elements
18-6
swap column
21-25
swap row
21-25
transposing
18-13
variables
18-1
matrix functions
18-10
COLNORM 18-10
COND
18-11
CROSS
18-11
DET
18-11
DOT
18-11
EIGENVAL
18-11
EIGENVV
18-11
IDENMAT
18-11
INVERSE
18-11
LQ
18-11
LSQ
18-11
LU
18-12
MAKEMAT
18-12
QR
18-12
RANK
18-12
ROWNORM
18-12
RREF
18-12
SCHUR
18-12
SIZE
18-12
SPECNORM
18-13
SPECRAD
18-13
SVD
18-13
SVL
18-13
TRACE
18-13
TRN
18-13
maximum real number
1-22, 13-8
memory R-20
clearing all
R-3
organizing
17-9
out of
R-21
saving
1-25, 22-1
viewing
17-1
menu lists
searching 1-9
minimum real number
13-8
mixed fraction format 1-11
modes
angle measure
1-10
CAS
14-5
decimal mark
1-11
number format
1-10
MODSTO
14-53
modular arithmetic 14-51
multiple solutions
plotting to find
7-7
multiplication
13-4, 14-28
implied
1-20
MULTMOD
14-54
N
name conflict R-21
naming
programs
21-4
natural exponential
13-4, 13-10
natural log plus 1
13-10
natural logarithm 13-4
negation
13-5
negative numbers 1-20
NEXTPRIME 14-51
no equations checked
R-21
non-rational 14-6
Normal Z-distribution, confidence in-
tervals
11-15
note
copying
20-8
editing
20-2
importing
20-8
printing
21-26
viewing
20-1
writing
20-1
Notepad
20-1
catalog keys
20-7
creating notes
20-6
writing in
20-6
nth root
13-6
null hypothesis 11-2
number format
engineering
1-11
fixed
1-10
fraction
1-11
in Solve aplet
7-5
hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
I-9
mixed fraction 1-11
scientific
1-10
Standard
1-10
numeric precision
17-9
Numeric view
adding values
2-19
automatic
2-16
build your own table
2-19
display defining function for col-
umn
2-17
recalculating
2-19
setup
2-16, 2-19
O
off
automatic 1-1
power
1-1
on/cancel
1-1
One-Proportion Z-Interval 11-17
One-Sample T-Interval 11-18
One-Sample T-Test
11-12
One-Sample Z-Interval 11-15
One-Sample Z-Test
11-8
online help 14-8
order of precedence 1-21
overlaying plots
2-15, 4-3
P
π 13-8
PA2B2
14-67
paired columns 10-11
parametric variables
axes
21-31
connect
21-31
grid
21-32
in menu map
R-8
indep
21-33
labels
21-34
recenter
21-34
ycross
21-37
parentheses
to close arguments
1-21
to specify order of operation
1-21
PARTFRAC
14-13, 14-57
partial derivative 14-16
partial fraction expansion 14-13
partial integration
14-18
pause 21-29
permutations
13-13
pictures
attaching in Sketch view
20-3
plot
analyzing statistical data in
10-19
auto scale
2-14
box-and-whisker
10-16
cobweb
6-1
comparing
2-5
connected points
10-17, 10-19
decimal scaling
2-14
defining the independent variable
21-36
drawing axes
2-7
expressions
3-3
grid points
2-7
histogram
10-15
in Solve aplet
7-7
integer scaling
2-14
one-variable statistics
10-18
overlay plot
2-13
overlaying
2-15, 4-3
scaling
2-13
scatter
10-15, 10-17
sequence
2-6
setting up
2-5, 3-2
split-screen view
2-14
splitting
2-14
splitting into plot and close-up
2-13
splitting into plot and table
2-13
stairsteps
6-1
statistical data
10-15
statistics parameters
10-18
t values
2-6
tickmarks
2-6
to capture current display
21-21
tracing
2-8
trigonometric scaling
2-14
two-variable statistics
10-18
plotting resolution
and tracing
2-8
plot-view variables
area
21-31
connect
21-31
fastres
21-32
function
21-31
grid
21-32
hmin/hmax
21-32
hwidth
21-33
isect
21-33
hp40g+.book Page 9 Friday, December 9, 2005 1:03 AM
I-10
labels 21-34
recenter
21-34
root
21-34
s1mark-s5mark
21-34
statplot
21-35
tracing
21-33
umin/umax
21-35
ustep
21-35
polar variables
axes
21-31
connect
21-31
grid
21-32
in menu map
R-9
indep
21-33
labels
21-34
recenter
21-34
ycross
21-37
polynomial
coefficients
13-11
evaluation
13-11
form
13-12
roots
13-12
Taylor
13-7
polynomial functions
POLYCOEF
13-11
POLYEVAL
13-11
POLYFORM
13-12
POLYROOT
13-12
ports
22-5
position argument
21-21
power (x raised to y) 13-5
powers
14-6
POWEXPAND
14-31
POWMOD 14-54
precedence
1-22
predicted values
statistical
10-20
PREVAL
14-23
PREVPRIME 14-51
prime factors 14-47
prime numbers
14-50, 14-51
primitive 14-23, 14-24
print
contents of display
21-25
name and contents of variable
21-26
object in history
21-25
variables
21-26
probability functions
!
13-13
COMB
13-12
RANDOM
13-13
UTPC
13-13
UTPF
13-13
UTPN
13-13
UTPT
13-14
program
commands
21-4
copying
21-8
creating
21-4
debugging
21-7
deleting
21-9
delimiters
21-1
editing
21-5
naming
21-4
pausing
21-29
printing
21-26
sending and receiving
21-8
structured
21-1
prompt commands
beep
21-26
create choose box
21-26
create input form
21-28
display item
21-27
display message box
21-29
halt program execution
21-29
insert line breaks
21-29
prevent screen display being up-
dated 21-28
set date and time
21-27
store keycode
21-28
PROPFRAC
14-58
PSI
14-67
Psi 14-68
PTAYL
14-58
Q
quadratic
extremum
3-6
fit
10-13
function
3-4
QUOT
14-58
QUOTE
14-13
quotes
in program names 21-4
R
random numbers 13-13
hp40g+.book Page 10 Friday, December 9, 2005 1:03 AM
I-11
RE 13-8
real number
maximum
13-8
minimum
13-8
real part
13-8
real-number functions
13-14
% 13-16
%CHANGE
13-16
%TOTAL
13-16
CEILING
13-14
DEGtoRAD
13-14
FNROOT
13-14
HMSto
13-15
INT
13-15
MANT
13-15
MAX
13-15
MIN
13-15
MOD
13-15
RADtoDEG
13-16
ROUND
13-16
SIGN
13-16
TRUNCATE
13-17
XPON
13-17
reatest common divisor
14-47
recalculation for table 2-19
receive error R-21
receiving
aplet
22-5
lists
19-6
matrices
18-4
programs
21-8
redrawing
table of numbers
2-18
reduced row echelon
18-12
regression
analysis
10-17
fit models
10-13
formula
10-12
user-defined fit
10-13
relative error
statistical
10-18
REMAINDER
14-59
REORDER 14-68
resetting
aplet
22-3
calculator
R-3
memory
R-3
result
copying to edit line
1-22
reusing
1-22
rigorous
14-6
RISCH
14-24
root
interactive 3-10
nth
13-6
variable
21-34
root-finding
displaying
7-7
interactive
3-9
operations
3-10
variables
3-10
S
S1mark-S5mark variables 21-34
scaling
automatic 2-14
decimal
2-10, 2-14
integer
2-10, 2-14, 2-15
options
2-13
resetting
2-13
trigonometric
2-14
scatter plot
10-15, 10-17
connected 10-17, 10-19
SCHUR decomposition
18-12
scientific number format 1-10, 1-20
scrolling
in Trace mode
2-8
searching
menu lists
1-9
speed searches
1-9
secant
13-20
Sending
22-5
sending
aplets
22-4
lists
19-6
programs
21-8
sequence
definition
2-2
sequence variables
Axes
21-31
Grid
21-32
in menu map
R-10
Indep
21-33
Labels
21-34
Recenter
21-34
Ycross
21-37
serial port connectivity
22-5
SERIES 14-24
setting
hp40g+.book Page 11 Friday, December 9, 2005 1:03 AM
I-12
date 21-27
time
21-27
SEVAL
14-68
SIGMA 14-68
SIGMAVX 14-69
SIGN
14-46
sign reversal 7-6
SIMPLIFY 14-32
simplify
14-68, 14-70
SINCOS 14-31, 14-40
sine 13-4
inverse hyperbolic
13-9
singular value decomposition
matrix
18-13
singular values
matrix
18-13
sketches
creating
20-5
creating a blank graphic
21-22
creating a set of
20-5
erasing a line
21-20
labeling
20-5
opening view
20-3
sets
20-5
storing in graphics variable
20-5
slope
3-10
soft key labels
1-2
SOLVE 14-37
solve
error messages
7-7
initial guesses
7-5
interpreting intermediate guesses
7-7
interpreting results
7-6
plotting to find guesses
7-7
setting number format
7-5
solve variables
axes
21-31
connect
21-31
fastres
21-32
grid
21-32
in menu map
R-11
indep
21-33
labels
21-34
recenter
21-34
ycross
21-37
SOLVEVX
14-38
sorting 22-6
aplets in alphabetic order
22-6
aplets in chronological order
22-6
elements in a list
19-9
spectral norm
18-13
spectral radius 18-13
square root 13-5
stack history
printing
21-25
stairsteps graph
6-1
standard number format 1-10
statistics
analysis
10-1
analyzing plots
10-19
angle mode
10-12
calculate one-variable
21-30
calculate two-variable
21-30
data set variables
21-40
data structure
21-40
define one-variable sample
21-30
define two-variable data set’s de-
pendent column
21-30
define two-variable data set’s in-
dependent column 21-30
defining a fit
10-12
defining a regression model
10-12
deleting data
10-11
editing data
10-11
frequency
21-30
inserting data
10-11
plot type
10-18
plotting data
10-15
predicted values
10-20
regression curve (fit) models
10-12
saving data
10-10
sorting data
10-11
specifying angle setting
10-12
toggling between one-variable
and two-variable
10-12
tracing plots
10-19
troubleshooting with plots
10-19
zooming in plots
10-19
statistics variables
Axes
21-31
Connect
21-31
Grid
21-32
Hmin/Hmax
21-32
Hwidth
21-33
in menu map
R-12
Indep
21-33
hp40g+.book Page 12 Friday, December 9, 2005 1:03 AM
I-13
Labels 21-34
Recenter
21-34
S1mark-S5mark
21-34
Ycross
21-37
step size of independent variable
21-36
step-by-step
14-6
STORE 14-14
storing
list elements
19-1, 19-4, 19-5,
19-6
matrix elements
18-3, 18-5, 18-6
results of calculation
17-2
value
17-2
strings
literal in symbolic operations
13-18
STURMAB
14-69
SUBST 14-15
substitution 14-14
SUBTMOD
14-55
subtract 13-4
summation function
13-11
symbolic
calculations in Function aplet
13-21
defining expressions
2-1
differentiation
13-21
displaying definitions
3-8
evaluating variables in view
2-3
setup view for statistics
10-12
symbolic calculations
14-1
symbolic functions
| (where)
13-18
equals
13-17
ISOLATE
13-17
LINEAR?
13-18
QUAD
13-18
QUOTE
13-18
Symbolic view
defining expressions
3-2
syntax
13-2
syntax errors 21-7
T
table
navigate around 3-8
numeric values
3-7
numeric view setup
2-16
TABVAR
14-27
TAN2CS2
14-40
TAN2SC 14-41
TAN2SC2 14-41
tangent
13-4
inverse hyperbolic 13-9
Taylor polynomial
13-7
TAYLOR0 14-27
TCHEBYCHEFF 14-59
TCOLLECT
14-41
tests 14-61
TEXPAND 14-15, 14-42
tickmarks for plotting
2-6
time 13-15
setting 21-27
time, converting
13-15
times sign 1-20
TLIN
14-43
tmax 21-36
tmin 21-36
too few arguments
R-21
TOOL menu 15-1
tracing
functions
2-8
more than one curve
2-8
not matching plot
2-8
plots
2-8
transcendental expressions
14-42
transmitting
lists
19-6
matrices
18-4
programs
21-8
transposing a matrix
18-13
Triangle Solver aplet
9-1
TRIG 14-43
TRIGCOS
14-44
trigonometric
fit
10-13
functions
13-20
scaling
2-10, 2-14, 2-15
trigonometry functions
ACOS2S
14-38
ACOT
13-20
ACSC
13-20
ASEC
13-20
ASIN2C
14-39
ASIN2S
14-39
ASIN2T
14-39
hp40g+.book Page 13 Friday, December 9, 2005 1:03 AM
I-14
COT 13-20
CSC
13-20
HALFTAN
14-40
SEC
13-20
SINCOS
14-40
TAN2CS2
14-40
TAN2SC
14-41
TAN2SC2
14-41
TRIGCOS
14-44
TRIGSIN
14-44
TRIGTAN
14-44
TRIGSIN
14-44
TRIGTAN 14-44
TRUNC 14-28
truncating values to decimal places
13-17
TSIMP 14-70
tstep
21-36
Two-Proportion Z-Interval 11-17
Two-Proportion Z-Test 11-11
Two-Sample T-Interval
11-19
Two-Sample T-test 11-14
Two-Sample Z-Interval
11-16
typing letters 1-6
U
UNASSIGN 14-15
UNASSUME 14-61
undefined
name
R-21
result
R-21
un-zoom
2-11
upper-tail chi-squared probability
13-13
upper-tail normal probability 13-13
upper-tail Snedecor’s F
13-13
upper-tail student’s t-probability
13-14
USB connectivity 22-5
user defined
regression fit
10-13
V
value
recall 17-3
storing
17-2
variables
aplet
17-1
CAS
14-4
categories
17-7
clearing
17-3
definition
17-1, 17-7, R-2
in equations
7-10
in Symbolic view
2-3
independent
14-6, 21-36
local
17-1
previous result (Ans)
1-23
printing
21-26
root
21-34
root-finding
3-10
step size of independent
21-36
types
17-1, 17-7
use in calculations
17-3
variation table
14-27
VARS menu
17-4, 17-5
vectors
column 18-1
cross product
18-11
definition of
R-2
VER
14-70
verbose
14-6
version 14-70
views
1-18
configuration 1-18
definition of
R-3
W
warning symbol 1-8
where command ( | ) 13-18
X
Xcross variable 21-36
XNUM 14-32
XQ
14-32
Y
Ycross variable 21-37
Z
Z-Interval 11-15
zoom 2-17
axes 2-12
box
2-9
center
2-9
examples of
2-11
factors
2-13
hp40g+.book Page 14 Friday, December 9, 2005 1:03 AM
I-15
in 2-9
options
2-9, 3-8
options within a table
2-18
out
2-9
redrawing table of numbers op-
tions
2-18
square 2-10
un-zoom
2-11
within Numeric view
2-18
X-zoom
2-9
Y-zoom
2-10
hp40g+.book Page 15 Friday, December 9, 2005 1:03 AM
hp40g+.book Page 16 Friday, December 9, 2005 1:03 AM
4


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