TI-84 Plus doesn't recognize Local keyword

I am learning how to code in TI-BASIC for my TI-84 Plus CE, so I wrote a Quadratic Formula program:

:Local A
:Local B
:Local C
:Local P
:Local Q
:Prompt A,B,C
:-B+√(B²-4AC)√(2A)→P
:-B-√(B²-4AC)√(2A)→Q
:"The actual program uses a negative sign, but SE can't display it
...

(Rest of program not relevant, I output the values of P and Q in a specific way)

When running, I get a syntax error on the first keyword Local. I looked it up and I seem to have the correct syntax, so what's going on, and how can I get around the error?

Solution

Local is used in 68k Ti basic. The calculators belonging to this family are listed here: http://tibasicdev.wikidot.com/68k:thecalcs, and TI-84 is not one of them. I would suggest looking at the ti-83 basic page instead (http://tibasicdev.wikidot.com/home). Since you are prompting for the variables anyways, there is no point in deleting them at the start, or declaring them as local. If you code in the actual calculator itself, when you are editing a program and press prgm, a list of available methods are listed. If you press + then the calculator shows the syntax. As far as I know, those commands are all that are available to you without using assembly.