Texas Instruments TI-89 사용자 설명서

Basic Function Graphing

309

From the Home Screen or a Program

You can also define and evaluate a function from the Home screen or a program.

•

Use the

Define

and

Graph

commands. Refer to:

“Graphing a Function Defined on the Home Screen” and “Graphing a Piecewise
Defined Function” in Additional Graphing Topics.

“Overview of Entering a Function” in Programming.

•

Store an expression directly to a function variable. Refer to:

“Storing and Recalling Variable Values” in Operating the Calculator.

“Creating and Evaluating User-Defined Functions” in Calculator Home Screen.

Note:

User-defined functions can have almost any name. However, if you want them to

appear in the Y= Editor, use function names

y1(x)

y2(x)

, etc.

Selecting Functions to Graph

Regardless of how many functions are defined in the Y= Editor, you can select the ones
you want to graph.

Selecting or Deselecting Functions

Press

8 # to display the Y= Editor.

A “Ÿ” indicates which functions will be graphed the next time you display the Graph
screen.