Texas Instruments TI-80 Manual

$TITLEPG.DOC TI-80, ENG, 135x205mm Bob Fedorisko Revised: 02/15/01 10:36 AM Printed: 02/15/01 10:38
AM Page 1 of 2
TI-80
GRAPHING CALCULATOR
GUIDEBOOK
TI-GRAPH LINK, Calculator-Based Laboratory, CBL, CBL 2, Calculator-Based Ranger, CBR,
Constant Memory, Automatic Power Down, APD, and EOS are trademarks of Texas
Instruments Incorporated.
Windows is a registered trademark of Microsoft Corporation.
Macintosh is a registered trademark of Apple Computer, Inc.
© 1995–1997, 2001 by Texas Instruments Incorporated.

$TITLEPG.DOC TI-80, ENG, 135x205mm Bob Fedorisko Revised: 02/15/01 10:36 AM Printed: 02/15/01 10:38
AM Page 2 of 2
Texas Instruments makes no warranty, either expressed or
implied, including but not limited to any implied warranties of
merchantability and fitness for a particular purpose, regarding any
programs or book materials and makes such materials available
solely on an “as-is” basis.
In no event shall Texas Instruments be liable to anyone for
special, collateral, incidental, or consequential damages in
connection with or arising out of the purchase or use of these
materials, and the sole and exclusive liability of Texas
Instruments, regardless of the form of action, shall not exceed the
purchase price of this calculator. Moreover, Texas Instruments
shall not be liable for any claim of any kind whatsoever against
the use of these materials by any other party.
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 with 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, you can 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 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/television
technician for help.
Caution: Any changes or modifications to this equipment not
expressly approved by Texas Instruments may void your authority
to operate the equipment.
Important
US FCC
Information
Concerning
Radio Frequency
Interference

Introduction iii
This manual describes how to use the TI.80 Graphing Calculator. Getting Started
gives a quick overview of its features. The first chapter gives general
instructions on operating the TI.80. Other chapters describe its interactive
features. The applications in Chapter 11 show how to use these features
together.
Using this Guidebook Effectively.................... viii
Glossary ......................................... xii
TI-80 Keyboard ................................... 2
First Steps ....................................... 3
TI-80 Menus...................................... 4
Entering a Calculation: Compound Interest ........... 5
Continuing a Calculation ........................... 6
Defining a Function: Box with Lid ................... 7
Defining a Table of Values.......................... 8
Zooming In on the Table ........................... 9
Changing the Viewing Window...................... 11
Displaying and Tracing the Graph ................... 12
Zooming In on the Graph........................... 13
Other TI-80 Features .............................. 14
Turning the TI-80 On and Off ....................... 1-2
Setting the Display Contrast ........................ 1-3
The Display ...................................... 1-4
Entering Expressions and Instructions ............... 1-6
The Edit Keys .................................... 1-8
Setting Modes .................................... 1-9
TI-80 Modes...................................... 1-10
Variable Names ................................... 1-12
Storing and Recalling Variable Values................ 1-13
Last Entry........................................ 1-14
Last Answer ...................................... 1-16
TI-80 Menus...................................... 1-17
The VARS and Y-VARS Menus...................... 1-19
EOS (Equation Operating System) .................. 1-20
Error Conditions ................................. 1-22
Table of Contents
Getting Started:
Do This First!
Chapter 1:
Operating the
TI-80

iv Introduction
Getting Started: Lottery Chances .................... 2-2
Using the TI-80 Functions .......................... 2-3
Keyboard Math Operations ......................... 2-4
MATH MATH Operations ........................... 2-7
MATH NUM (Number) Operations ................... 2-10
MATH PRB (Probability) Operations................. 2-12
ANGLE Operations ................................ 2-14
TEST (Relational) Operations....................... 2-16
Getting Started: Working with Fractions ............. 3-2
Setting Modes for Fraction Results .................. 3-4
Entering and Using Fractions in Calculations ......... 3-6
The FRACTION Menu.............................. 3-8
Getting Started: Graphing a Circle ................... 4-2
Defining a Graph.................................. 4-3
Setting Graph Modes .............................. 4-4
Defining Functions in the Y= List.................... 4-5
Evaluating Y= Functions in Expressions ............. 4-7
Selecting Functions ............................... 4-8
Defining the Viewing Window ...................... 4-9
Displaying a Graph ................................ 4-11
Exploring a Graph with the Free-Moving Cursor ...... 4-12
Exploring a Graph with TRACE ..................... 4-13
Exploring a Graph with ZOOM...................... 4-15
Setting the Zoom Factors .......................... 4-18
Getting Started: Path of a Ball ...................... 5-2
Defining and Displaying a Parametric Graph .......... 5-3
Exploring a Parametric Graph ...................... 5-6
Chapter 2:
Math, Angle, and
Test Operations
Chapter 3:
Fractions
Chapter 4:
Function
Graphing
Chapter 5:
Parametric
Graphing

Introduction v
Getting Started: Roots of a Function ................. 6-2
Defining the Independent Variable .................. 6-3
Defining the Dependent Variable .................... 6-4
Displaying the Table............................... 6-5
Getting Started: Shading a Graph.................... 7-2
DRAW DRAW Menu ............................... 7-3
Drawing Lines .................................... 7-4
Drawing Horizontal and Vertical Lines ............... 7-5
Drawing a Function ............................... 7-6
Shading Areas on a Graph .......................... 7-7
Drawing Points ................................... 7-10
Clearing a Drawing ................................ 7-12
Getting Started: Generating a Sequence .............. 8-2
About Lists....................................... 8-3
LIST OPS Operations .............................. 8-6
LIST MATH Operations ............................ 8-9
Getting Started: Building Height and City Size......... 9-2
Setting Up a Statistical Analysis..................... 9-8
The STAT List Editor .............................. 9-9
Viewing, Entering, and Editing Lists ................. 9-10
Sorting and Clearing Lists .......................... 9-13
Statistical Analysis ................................ 9-14
Types of Statistical Analysis ........................ 9-15
Statistical Variables ............................... 9-17
Statistical Plotting ................................ 9-18
Statistical Analysis in a Program .................... 9-22
Statistical Plotting in a Program..................... 9-23
Chapter 6:
Tables
Chapter 7:
Draw Operations
Chapter 8:
Lists
Chapter 9:
Statistics

vi Introduction
Getting Started: Rolling a Die ....................... 10-2
About TI-80 Programs ............................. 10-4
Creating and Executing Programs ................... 10-5
Editing Programs ................................. 10-6
PRGM CTL (Control) Instructions ................... 10-7
PRGM I/O (Input/Output) Instructions ............... 10-11
Calling Other Programs ............................ 10-14
Probability Experiments: Coins, Dice, and Spinners ... 11-2
The Unit Circle and Trigonometric Curves............ 11-3
Program: Newton’s Numerical Solve Routine ......... 11-4
Program: Numerical Integration..................... 11-6
Program: Window Variables Store and Recall ......... 11-8
Graphing the Inverse of a Function .................. 11-10
Graphing a Piecewise Function ..................... 11-12
Graphing Inequalities .............................. 11-14
Graphing a Polar Equation ......................... 11-15
Program: Guess the Coefficients .................... 11-16
Checking Available Memory ........................ 12-2
Deleting Items from Memory ....................... 12-3
Resetting the TI-80 ................................ 12-4
Chapter 10:
Programming
Chapter 11:
Applications
Chapter 12:
Memory
Management

Introduction vii
Table of TI-80 Functions and Instructions ............ A-2
Menu Map........................................ A-20
TI-80 Variables ................................... A-26
Battery Information ............................... B-2
Accuracy Information ............................. B-8
In Case of Difficulty ............................... B-10
Service and Support Information ................... B-14
Warranty Information.............................. B-15
Appendix A:
Tables and
Reference
Information
Appendix B:
Service and
Warranty
Information
Index

viii Introduction
The structure of the TI-80 guidebook and the design of its pages can help you
find the information you need quickly. Consistent presentation techniques are
used throughout to make the guidebook easy to use.
The guidebook is designed to teach you how to use the
calculator.
¦Getting Started is a fast-paced, keystroke-by-keystroke
introduction.
¦Chapter 1 describes general operation and lays the
foundation for Chapters 2 through 10, which describe
specific functional areas of the TI-80. Most chapters begin
with a brief Getting Started introduction.
¦Chapter 11 contains application examples that incorporate
features from different functional areas of the calculator.
These examples can help you see how different functional
areas work together to accomplish meaningful tasks.
¦Chapter 12 describes memory management.
When possible, units of information are presented on a single
page or on two facing pages. Several page-design elements
help you find information quickly.
¦Page headings—The descriptive heading at the top of the
page or two-page unit identifies the subject of the unit.
¦General text—Just below the page heading, a short
section of bold text provides general information about
the subject covered in the unit.
¦Left-column subheadings—Each subheading identifies a
specific topic or task related to the page or unit subject.
Using this Guidebook Effectively
Structure of the
Guidebook
Page-Design
Conventions

Introduction ix
¦Specific text—The text to the right of a subheading
presents detailed information about that specific topic or
task. The information may be presented as paragraphs,
numbered procedures, bulleted lists, or illustrations.
¦Page “footers”—The bottom of each page shows the
chapter name, chapter number, and page number.
Several conventions are used to present information concisely
and in an easily referenced format.
¦Numbered procedures—A procedure is a sequence of
steps that performs a task. In this guidebook, each step is
numbered in the order in which it is performed. No other
text in the guidebook is numbered; therefore, when you
see numbered text, you know you should perform the
steps sequentially.
¦Lists with bullets—If several items have equal
importance, or if you may choose one of several
alternative actions, this guidebook precedes each item
with a “bullet” (¦) to highlight it—like this list.
¦Tables and charts—Sets of related information are
presented in tables or charts for quick reference.
¦Keystroke examples—The Getting Started examples
provide keystroke-by-keystroke instructions, as do the
numerous short examples and several detailed examples
that are identified with a .
Information-
Mapping
Conventions

x Introduction
Several techniques have been used to help you look up
specific information when you need it. These include:
¦A chapter table of contents on the first page of each
chapter, as well as the full table of contents at the front of
the guidebook.
¦A glossary at the end of this section, defining important
terms used throughout the guidebook.
¦An alphabetical table of functions and instructions in
Appendix A, showing their correct formats, how to access
them, and page references for more information.
¦Information about system variables in Appendix A.
¦A table of error messages in Appendix B, showing the
messages and their meanings and giving problem-handling
information.
¦An alphabetical index at the back of the guidebook, listing
tasks and topics you may need to look up.
Reference Aids