# TI-BASIC:Fnon

**Command Summary**

Turns on equations in the Y= editor (all of them, or only the ones specified)

**Command Syntax**

FnOn [*equation numbers*]

**Menu Location**

Press:

- VARS to access the variables menu.
- RIGHT to access the Y-VARS submenu.
- 4 to select On/Off..., or use arrows and ENTER.
- ENTER to select FnOn.

TI-83/84/+/SE

1 byte

The FnOn command is used to turn on equations in the current Graphing_Mode. When you define an equation, it's turned on by default, but the FnOff command can turn an equation off (in which case, it's still defined, but isn't graphed). To turn functions on and off manually, put your cursor over the = symbol in the equation editor, and press enter.

When FnOn is used by itself, it will turn on all defined equations in the current graphing mode. You can also specify which equations to turn on, by writing their numbers after FnOn: for example, FnOn 1 will turn off the first equation, and FnOn 2,3,4,5 will turn the second, third, fourth, and fifth. The numbers you give FnOn have to be valid equation numbers in the graphing mode. When turning equations on and off in sequence mode, use 1 for u, 2 for v, and 3 for w.

The most common use for FnOn and FnOff is to disable functions when running a program, so that they won't interfere with what you're doing on the graph screen, then enable them again when you're done.

# Error Conditions

**ERR:DOMAIN**is thrown if an equation number isn't valid in the current graphing mode, or at all.