Texas Instruments TI-82 Getting Started page 5

Hide thumbs Also See for TI-82:

The factorial of a nonnegative integer is the product of all the integers from 1 up to the given integer. The

symbol for factorial is the exclamation point. So 4! (pronounced four factorial ) is

will learn more about applications of factorials in your textbook, but for now use the TI-82 to calculate 4!

The factorial command is located in the MATH menu's PRB sub-menu. to compute 4!, press these

keystrokes: 4 MATH

Note that you can select a sub-menu from the MATH menu by pressing either

once than to press

three times to get to the PRB sub-menu.

I.2 Functions and Graphs

I.2.1 Evaluating Functions: Suppose you received a monthly salary of $1975 plus a commission of

10% of sales. Let

1975

.10x.

If your January sales were $2230 and your February sales were $1865, what was your income during

those months?

Here's one method to use your TI-82 to perform this task. Press the Y= key at the top of the calculator to

display the function editing screen (Figure I.6). You may enter as many as ten different functions for the

TI-82 to use at one time. If there is already a function

move the cursor to

and then press CLEAR to delete whatever was there. Then enter the expression

by pressing these keys: 1975 + .10 X,T, . (The X,T, key lets you enter the variable X easily

1975

.10x

without having to use the ALPHA key.) Now press 2nd QUIT to return to the main calculations screen.

Figure I.6: Y= screen

Technology Guide

Graphing

Figure I.5: MATH menu

4 ENTER or 4 MATH

your sales in dollars; then your wages

ENTER ENTER.

in dollars are given by the equation

, press

as many times as necessary to

Figure I.7: Evaluating a function

1 2 3 4

24.

You

or . It is easier to press

I-5