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

FnOn numbers//

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.

# Related Commands

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