Operation Manual

Chapter 3: Function Graphing 75
Defining or Editing a Function
To define or edit a function, follow these steps.
1. Press o to display the Y= editor.
2. Press † to move the cursor to the function you want to define or edit. To erase a function, press
‘.
3. Enter or edit the expression to define the function.
• You may use functions and variables (including matrices and lists) in the expression. When the
expression evaluates to a nonreal number, the value is not plotted; no error is returned.
• You can access the shortcut menus by pressing ƒ ^
- a.
• The independent variable in the function is X.
Func mode defines „ as X. To enter X, press
„ or press ƒ [X].
• When you enter the first character, the = is highlighted, indicating that the function is selected.
As you enter the expression, it is stored to the variable
Yn as a user-defined function in the
Y= editor.
4. Press Í or † to move the cursor to the next function.
Note: If you are working in MathPrint™ mode and edit your entry, be sure to delete all empty
MathPrint™ template boxes before pressing s. An empty MathPrint™ box causes an error, and the
TI-84 Plus C will not graph.
Defining a Function from the Home Screen or a Program
To define a function from the home screen or a program, begin on a blank line and follow these steps.
1. Press ƒ
[ã], enter the expression, and then press ƒ [ã] again.
2. Press ¿.
3. Press ƒ a to display the
YVAR shortcut menu, move the cursor to the function name, and then
press Í.
Empty MathPrint™ box causes
error in graph.