So this is for the TI-83 calculator. I don't know what language it is, so for know, I will refer to it as Ti-83.

*Note: Items in all caps are accesible under PRGM. Items in () are not on the keyboard. Ex. (squareroot)

Code:
:INPUT "a?",A
:INPUT "b?",B
:INPUT "c?",C
:b^2-4ac -> D
:(squareroot)D -> E
:-b+E -> F
:-b--E -> G
:f/(2a) -> H
:g/(2a) -> I
:DISP H
:DISP I
This will display what values of X fit the equation. It will not work if the parabola does not instersect the X-axis. I'll post a program that factors that when I get done with it. For now, enjoy this little program. This is especially helpful in Algebra 1 & 2.

~Fluxo