User Guide

Chapter 3: Function Graphing 69
3. Press ƒ a to display the YVAR shortcut menu, move the cursor to the function name,
and then press
Í.
"expression"!Yn
When the instruction is executed, the TI-84 Plus stores the expression to the designated variable
Yn, selects the function, and displays the message Done.
Evaluating Y= Functions in Expressions
You can calculate the value of a Y= function
Yn at a specified value of X. A list of values returns a list.
Yn(value)
Yn({value1,value2,value3, . . .,value n})
Selecting and Deselecting Functions
Selecting and Deselecting a Function
You can select and deselect (turn on and turn off) a function in the Y= editor. A function is selected
when the
= sign is highlighted. The TI-84 Plus graphs only the selected functions. You can select
any or all functions Y1 through Y9, and Y0.
To select or deselect a function in the Y= editor, follow these steps.
1. Press o to display the Y= editor.
2. Move the cursor to the function you want to select or deselect.
3. Press | to place the cursor on the function’s = sign.
4. Press Í to change the selection status.
When you enter or edit a function, it is selected automatically. When you clear a function, it is
deselected.