The x-coordinate of [math]B[/math] is always the x-coordinate of [math]A+2^n[/math]. Notice what happens to the gradient of [math]AB[/math] as after you press start. *Point [math]B[/math] will approach Point [math]A[/math].* [list] [*]You may adjust [math]a, b[/math] and [math]c[/math] freely to get different quadratic curves. [*]You may also adjust Point [math]A[/math] freely. It will always be on the curve. [/list]
I hope you have made use of this to understand limits better! :D