83Plus:Basic:Graphics:DrawInv

DrawInv draws the function as if the Y and X values were switched. The following draws the inverse of y=x²:

DrawInv X^2

You should see a parabola starting at (0,0) moving off to the right.

Also you can use equations instead of strings. The following draws the inverse of the equation in Y₁:

DrawInv Y1

You can access the equation variables by hitting [Vars], [Right] to Y-Vars, and finally to Functions.