I want to use the "Calculate-Intersect" in a program, but when going to the sub-menu in a program editor it just puts me in the users screen and not a command. Are there any commands / ways of getting and solving x or y's with a y1?
3 Answers
You can effectively find the intersect of two Y variables in TI-83 Basic by using the solve() function.
Assuming Y1 and Y2, and N is a guess of what the x value of the intersect is (you could just use 0), are the two functions that you want to find the intersect of, then:
solve(Y1 - Y2, X, N) → A
will store the x coordinate of the intersect to A, and then:
A → X
Y1 → B
will store the Y value of the intersect to B.
This is probably the fastest way to find the intersect of two functions in TI-83 basic because it relies on inbuilt functions instead of slow loops to find the intersect.
Edit:
As pointed out by Sentherus Argentum in the comments, the y value of the coordinate can be stored to B with just Y1(A) → B

- 1,065
- 10
- 27
-
If you want to avoid storing to X and would prefer the answer immediately, just use Y1(A) to get the value for B. – Zenohm Jun 24 '15 at 21:30
-
@Sentherus Argentum I haven't used a ti-84 since I upgraded to the ti-88, so I wasn't sure if that was valid in TI83-Basic – Vaelus Jun 24 '15 at 21:54
-
It still is, just wanted to make sure that it's known to those who might want to use it. – Zenohm Jun 24 '15 at 22:01
As far as I'm aware Ti-Basic has only got commands to find stuff about single funtions like the fMin(
, fMax(
and solve(
commands. I'm afraid the ti-basic language has no access to the CALC-Menu options.

- 98
- 4
- 12
Something like this?
:For(X,Xmin,Xmax,ΔX)
:If Y1(X)=Y2(X):Then
:Y1(X)→Y :Disp X,Y :Xmax→X
:Else
:(Y1(X)-Y2(X))/abs(Y1(X)-Y2(X))→Z
:(Y1(X-ΔX)-Y2(X-ΔX))/abs(Y1(X-ΔX)-Y2(X-ΔX))→W
:If W≠Z:Then
:Y1(X)→Y :Disp X,Y :Xmax→X:End
:End
:End

- 1
- 1
- 2