Texas Instruments TI-82 STATS User manual

GRAPHING CALCULATOR KEYSTROKE GUIDE
to accompany
ELEMENTARY ALGEBRA: DISCOVERY AND
VISUALIZATION
2nd Edition
Karl M. Zilm
Lewis & Clark Community College
HOUGHTON MIFFLIN COMPANY BOSTON NEW YORK

Editor in Chief: Charles Hartford
Associate Editor: Mary Beckwith
Senior Manufacturing Coordinator: Sally Culler
Marketing Manager: Ros Kane
Copyright © 1999 by Houghton Mifflin Company. All rights reserved.
No part of this work may be reproduced or transmitted in any form or by any means, electronic or
mechanical, including photocopying and recording, or by any information storage or retrieval system
without prior written permission of Houghton Mifflin Company unless such copying is expressly
permitted by federal copyright law. Address inquiries to College Permissions, Houghton Mifflin
Company, 222 Berkeley Street, Boston, MA 02116-3764.
Printed in the U.S.A.
ISBN: 0-395-937736
123456789-HS-03 02 01 00 99

iii
Preface
This Guide is designed for students using a Texas Instruments TI-82 or TI-83 graphing calculator in
conjunction with the textbook Elementary Algebra: Discovery and Visualization, 2nd edition, by
Hubbard and Robinson. There is a separate section of the Guide for each calculator model. The TI-82
section begins on page 1; the TI-83 section begins on page 27. The following description of the Guide
and how to use it applies to both sections.
The Guide assumes no prior experience in using a graphing calculator. Therefore, it begins with
an Introduction chapter dealing with the basics: how to turn the calculator on, how to turn it off, how
to adjust the screen contrast, and how to enter and edit basic arithmetic expressions. You should
probably go through the Introduction chapter of this Guide as soon as you get your calculator. The
Introduction chapter will give you an opportunity to familiarize yourself with the basic operation of
your calculator so that you will be ready to learn the other features described later in the Guide.
The Introduction chapter is followed by the Graphing Calculator Keystroke Guide, which is
keyed to the textbook. As you look at the pages in the textbook, you will notice that in the left margin
of some pages a book icon &appears next to a key word or phrase, with a brief reference to a related
feature on the graphing calculator appearing in the body of the text. Corresponding to each of these
key words or phrases in the textbook, this Guide provides a detailed description of how to use the
related feature on your particular graphing calculator model. In the Guide each key word or phrase is
printed as it appears in the textbook, and on the line above it is the number of the page on which it
appears in the textbook. Each key word or phrase will also have its own number (in boldface type)
for easy future reference. For example, on page 14 in the textbook you will find a book icon in the left
margin with the key words “Absolute Value” next to it and a brief reference in the body of the text to
the calculator notation ABS. If you are using a TI-82 graphing calculator, look on page 9 in this
Guide. If you are using a TI-83, look on page 35 in this Guide. You will see a reference to the
absolute value feature:
page 14
10 Absolute Value,
followed by a description of how to enter expressions involving absolute values on your calculator.
The boldface number 10 is a reference number which may be used later in the Guide to refer you
quickly to this description of the absolute value feature.
As you begin to use the Guide to read about the key words and phrases, you may want to keep a
bookmark in the Guide at the most recently examined key word or phrase. If you go through the
chapters of the textbook in the order they are printed, you will encounter the new key words and
phrases in the order they are printed in this Guide. Thus, your bookmark will usually be at or near the
next key word or phrase you will want to read about, and you will be able to refer to it quickly when
needed.
I would like to thank the authors of the textbook, Elaine Hubbard and Ronald D. Robinson, and
the staff of Houghton Mifflin, particularly Charles Hartford, Editor in Chief; and Kathy Yoon,
Editorial Assistant, for their support and assistance in the production of this Guide.
Karl M. Zilm

iv
Contents
TI-82
INTRODUCTION: On/Off, Contrast, Mode, and Editing Expressions 1
Turning the Calculator On 1
Adjusting the Display Contrast (Making the Screen Lighter or Darker) 1
Turning the Calculator Off 2
Second Functions for Keys—Notation 2
Mode 2
Editing Expressions 3
TI-82 GRAPHING CALCULATOR KEYSTROKE GUIDE 5
Items highlighted with bullets • only direct you to earlier references on the same subject.
1Divide 5
2Decimal 5
3Square Root 6
4Add 6
5Negative and Subtract 7
6Multiply 8
7•Divide 8
8Exponent 8
9•Square Root 9
10 Absolute Value 9
11 Reciprocal 9
12 •Negative 10
13 Fraction 10
14 Store 10
15 Alpha 10
16 Window and Default 11
17 Integer 12
18 Graph 13
19 Cursor 13
20 Enter Function 14
21 Evaluate Y 14
22 Table 16
23 Trace 17
24 Test 18
25 Zoom In 19
26 Square 20
27 Shade 20
28 Solve 22
29 Evaluate Y 26
30 Scientific 26

Contents v
TI-83
INTRODUCTION: On/Off, Contrast, Mode, and Editing Expressions 27
Turning the Calculator On 27
Adjusting the Display Contrast (Making the Screen Lighter or Darker) 27
Turning the Calculator Off 28
Second Functions for Keys—Notation 28
Mode 28
Editing Expressions 29
TI-83 GRAPHING CALCULATOR KEYSTROKE GUIDE 31
Items highlighted with bullets • only direct you to earlier references on the same subject.
1Divide 31
2Decimal 31
3Square Root 32
4Add 32
5Negative and Subtract 33
6
Multiply 34
7•Divide 34
8Exponent 34
9•Square Root 35
10 Absolute Value 35
11 Reciprocal 36
12 •Negative 36
13 Fraction 36
14 Store 36
15 Alpha 37
16 Window and Default 37
17 Integer 39
18 Graph 40
19 Cursor 40
20 Enter Function 40
21 Evaluate Y 41
22 Table 42
23 Trace 44
24 Test 45
25 Zoom In 45
26 Square 47
27 Shade 47
28 Solve 50
29 Evaluate Y 55
30 Scientific 56
INDEX 57

1
TI-82 INTRODUCTION
On/Off, Contrast, Mode, and Editing
Expressions
TURNING THE CALCULATOR ON
When the ON button is pressed, you should see a blinking dark rectangle (called the cursor) in the
upper left-hand corner of the screen. The screen you are looking at is called the Home screen, where
basic computations are performed. If you do not see the blinking cursor, you may need to adjust the
display contrast. How that is done will be described next.
ADJUSTING THE DISPLAY CONTRAST (MAKING THE SCREEN LIGHTER OR
DARKER)
Even if your display is presently easy to view, you may find that under different lighting conditions you
may need to adjust the display contrast. Also, as the batteries in your calculator become weaker with
use, you will have to make occasional adjustments in display contrast.
If you wish to make the display darker, press the light blue 2nd key and then hold down the Up
Arrow (
∆
) key until the desired level of darkness is obtained. If you wish to make the display lighter,
press the light blue 2nd key and then hold down the Down Arrow (
∇
) key until the desired level of
darkness is obtained. As soon as you release the Up Arrow or Down Arrow key, the arrow keys no
longer affect contrast, and you must press the 2nd key again to make the arrow keys affect the
contrast.
Note that when the 2nd key is pressed, an arrow pointing upward appears inside the cursor to let
you know that the 2nd key has been pressed. (Why the arrow pointing upward denotes the 2nd key will
be explained a bit later.) The Up, Down, Left, and Right Arrow keys are the blue-gray keys located in
the upper right-hand portion of the keyboard. In many of the other uses we will have for them, they will
function in the same way as the arrow keys on a computer keyboard.
Experiment with the contrast setting a bit. You will find that when you press 2nd and hold down
∆
or press 2nd and hold down
∇
, a cursor with a number in it will appear in the upper right-hand corner

2TI-82 Introduction
of the Home screen as long as you hold down the Up Arrow or Down Arrow key. Try to adjust the
contrast, and as you do, be looking in the upper right-hand corner of the screen for the contrast
number. This number indicates how dark, on a scale of 0 to 9, you have made your screen, with 9
representing the darkest possible contrast setting. As the batteries in your calculator become weaker,
the contrast setting usually needs to be increased to provide the same level of contrast you may have
obtained at a lower setting with fresh batteries. When you need to set the contrast setting to 8 or 9 on a
regular basis to see the display clearly, it is time to change batteries.
When is the contrast set appropriately? To some extent it is a matter of personal preference, but
there are some contrast qualities which most people find suitable. The screen is composed of tiny
squares, called pixels, which darken to form the cursor, numbers, letters, etc., on the screen. Most
people find that the contrast is set about right when the cursor is clearly visible and you can see that it
is composed of 7 rows and 5 columns of pixels. You should also just barely be able to see where the
other pixels are on the screen, but they should by no means be dark, just barely visible if you look
closely.
TURNING THE CALCULATOR OFF
Pressing the 2nd key before pressing the ON key activates the ON key's second function, which is
printed in light blue print above the ON key. Notice the word OFF written on the keyboard above the ON
key. Thus, pressing the 2nd key and then the ON key turns the calculator off.
If you forget to turn the calculator off, it will turn itself off after a few minutes of non-use, using
the Automatic Power Down (APD™) feature. Pressing the ON key turns the calculator back on, and
the screen will appear exactly as it was before the (APD™) feature turned the calculator off.
SECOND FUNCTIONS FOR KEYS—NOTATION
To simplify matters in the future when referring to second functions served by keys, this Keystroke
Guide will simply show 2nd followed by the name of the second function, enclosed in brackets. For
example the keystroke sequence for turning the calculator off will be denoted 2nd [OFF]. Thus, the word
in brackets is not on the key itself, but it is written above the key in light blue print as the key's second
function. This is why, when you press the 2nd key, the arrow pointing upward appears inside the
cursor. It is to remind you to look for the light blue print above a key, rather than what is written on
the key, to determine what that key will do when you press it.
MODE
Before doing some basic computations, it would be a good idea to check the mode settings on the
calculator which determine how results are displayed. Press the MODE key. The display should appear
as shown at the top of the next page.

TI-82 On/Off, Contrast, Mode, and Editing Expressions 3
For now, it would be best to have all of the settings on each line highlighted (black background) as
shown. If any of the highlighted settings on your calculator are not the ones shown above, use your
Arrow keys to move the blinking cursor over the setting desired and press ENTER. Continue in a like
manner until all of the settings on the left side are highlighted as shown. Press 2nd [QUIT] to return to
the Home screen.
EDITING EXPRESSIONS
Turn on your calculator and type in
3
2
7
+
×
. (Don't worry just yet about calculating the value of the
expression.) The calculator displays 3+2*7. Note that the calculator displays multiplication with an
asterisk (*). This is a common computer notation for multiplication.
Entering an expression and editing it before evaluation
As you can already see, the TI-82 differs from ordinary scientific calculators in more ways than just
being able to draw graphs. One of its major advantages as a calculator is that it enables you to see an
entire arithmetic expression as you enter it. The TI-82 also lets you easily edit the expression both
before and after you evaluate it. To see how to edit, we will change the expression above, replacing the
2 with a 4. Use the Left Arrow key (
<
) to move the cursor until it is over the 2. Type a 4. The
expression should now look like this: 3+4*7. We will now evaluate the expression. The cursor is still
in the middle of the expression, but that doesn't matter. To evaluate the expression press the ENTER key
in the lower right-hand corner of the keyboard. On the right-hand side of the calculator screen you
should see 31 displayed, which is the value of the expression. Note that the calculator uses standard
algebraic order of operations rules, performing the multiplication before the addition.
Editing an expression after evaluation
Suppose you wanted to evaluate
3
5
7
+
×
. Since this expression differs from the previous one in only
one character (5 instead of 4), there is a way we can quickly obtain the new expression from the old.
Rather than enter the entire expression again, just press 2nd [ENTRY]. An exact copy of the last
expression entered is reproduced on the screen. Now use the arrow keys as before to change the 4 to a
5, and press ENTER to obtain the value of the new expression, 38.
INS (Insert) and DEL (Delete)
Suppose we want to evaluate
3
4
85
7
6
+
×
.
.
by editing the last expression. If we press 2nd [ENTRY], we
get 3+5*7 on the display. Move the cursor over the 5. We have one problem here that we must
recognize: if we type in 4.85, we will type over part of the expression we want to keep. To avoid that,
type the 4 over the 5, and then press 2nd [INS], which puts the calculator in Insert mode. Note that the
cursor becomes a blinking underline. That means that the character at the cursor position and all those
to the right of it will be moved to the right to make room for some inserted symbols. Type in the
remaining .85 to complete the 4.85 and see how the other characters are moved to the right to make

4TI-82 Introduction
room. Now use the arrow keys to put the cursor at the end of the expression. Note that as soon as you
move the cursor with an arrow key, the calculator leaves Insert mode. We are now going to change 7 to
7.6. Since the cursor is at the end of the expression, the calculator need not be in Insert mode to make
this change (though it would make the change just the same if it were in Insert mode). After the 7 type
in .6, and press ENTER to display the value of the new expression, 39.86.
Now suppose we want to evaluate
3
5
2
7
6
+
×
.
.
by editing the last expression. Press 2nd [ENTRY] to
reproduce the last expression, and use the arrow keys to place the cursor over the 4. Type in 5.2. Since
5.2 contains one less character than 4.85, the last digit of the 4.85 is still on the screen and must be
eliminated. The cursor should now be resting on this last digit (5) of the old 4.85. Press the DEL key to
delete this character. (Each time the DEL key is pressed, it deletes the character at the cursor position.)
Press ENTER to display the value of the expression, 42.52.
Next, suppose we want to evaluate
3
5
8
+
×
. Notice that this expression could be produced by
editing the last expression we evaluated, but it really looks more like the expression 3+5*7 that we
evaluated some time earlier. One of the nice features of the TI-82 is that it stores as many previous
entries as it can. Press 2nd [ENTRY] once to produce the last expression. Now press 2nd [ENTRY] again.
Note that you now see the next-to-last expression we evaluated. If you press 2nd [ENTRY] one more
time, you will see the expression we evaluated before that, which was 3+5*7. You may now edit this
expression as before to produce 3+5*8. Press ENTER to evaluate it. If you continue to press 2nd
[ENTRY] beyond the calculator's ability to recall previous entries, it will return you to the most recently
evaluated expression.
Clearing the Home screen
By now your Home screen may look pretty full, and the original expressions you entered may have
scrolled off the top of the screen. Any time you want to erase everything on the Home screen, just press
the CLEAR key, located below the arrow keys. If you want to retrieve these erased expressions, you may
still do so by pressing 2nd [ENTRY] as often as needed.

5
TI-82 GRAPHING CALCULATOR
KEYSTROKE GUIDE
As you look at the pages in your textbook, you will notice that on some pages a book icon &appears
with a brief description of a feature on your TI-82 graphing calculator. In this guide the page number
in the textbook on which each of these book icons occurs is shown, as well as the key word or phrase
which appears next to the icon, followed by a detailed description of how to use this feature on your
TI-82. Each feature is also given its own number for easy reference.
page 3
1Divide
The symbol ÷appears on the division key of the TI-82, but on the screen division is indicated by
the diagonal slash /. Do the division 24 divided by 6 by pressing 24 ÷6 ENTER. Note that on the
home screen the division appears as 24/6, which means the same thing, and the result is still 4.
Fractions may also be entered as divisions. For example, the fraction 4
3may be interpreted as
3 divided by 4. You may enter the fraction that way on your calculator. On the screen you will see
3/4. When you press ENTER, you will see the decimal equivalent of .75. (See also 13 Fraction.)
page 4
2Decimal
Press the MODE key. Notice that on the second line of mode settings the word Float is probably
highlighted. If not, move the blinking cursor over the word Float and press ENTER. Press 2nd
[QUIT] to return to the Home screen. Unless the computation comes out exactly using fewer digits,
when the calculator is set to Float mode, the calculator displays 10 digits, and the decimal point
occurs at its appropriate place in the 10-digit display. As a result, sometimes more digits are
displayed to the right of the decimal point on some computations than on others. The decimal
point "floats" to wherever it should be in the 10-digit display for a given computation. For
example, perform the following three divisions: 17÷8, 368÷7, and 9543÷7. Since the computation
of 17÷8 comes out exactly at the third decimal place, the calculator displays only the number of
decimal places needed to show the result: 2.125. The other two computations do not come out
exactly, no matter how many decimal places are used, so the calculator displays ten digits and
locates the decimal point where it should occur in the 10-digit display: 368÷7 = 52.57142857 and