2 functions and graphs – Texas Instruments TI-85 User Manual

Page 11

Chapter 1

B-11

Evaluate

at x = 7 by recalling the previous entry with

2nd

ENTER

(

ENTRY

) , edit the 5 to 7 by pressing

and typing over the 5, and press

ENTER

Repeat the process to evaluate

at x = 10.

1.2 Functions and Graphs

When you are asked to estimate or approximate an output or an input value, you can use your
calculator in the following ways:

tracing a graph

(Sections 1.1.5, 1.1.6)

close values obtained from a table of function values

(End of Section 1.2.2)

When you are asked to find or determine an output or an input value, you should use your
calculator in the following ways:

evaluating an output on the home screen

(Section 1.1.7)

find a value using the

AUTO

ASK

features of the table

(Section 1.2.1)

determine an input using the solver

(Section 1.2.2)

1.2.1 DETERMINING OUTPUTS

Function outputs can be determined by evaluating on t h e

home screen, as discussed in 1.1.7. You can also evaluate functions using the calculatorÕs

TABLE

. (On the TI-85, the table is accessed with program

TABLE

.) When you use the table,

you can ask for specific output values corresponding to the inputs you enter or generate a list
of input values that begin with

TblMin

and differ by

Tbl

and their corresponding outputs.

LetÕs use the

TABLE

to determine the output of the function v(t) = 3.622(1.093)

when t =85.

Press

GRAPH

(

y(x)=

) , clear any functions, and enter 3.622(1 .093)^

in location

. Exit.

TI-85

Note that when using program

TABLE,

any

functions you want to evaluate should be in locations

, and so forth. That is, donÕt leave an empty

function location in the

y(x)=

list. (Program

TABLE

can be found in the TI-85/86 Appendix.)

An alphabetical list of the programs that you have
entered in your TI-85 appears on the bottom menu.

Press

PRGM

and then press

(

NAMES

) .

Find the name

TABLE

(press

if necessary).

Press the

-key corresponding to the location of the

program and

ENTER

to ÒrunÓ the program.

Since we only want v(85), enter

for

ASK

and type

at the

x=?

prompt.