You will see the following screen.
This is very similar to the Family of Curves screen, the only differences being the Speed bar and Reverse. Speed controls the speed of the animation.
Put in your settings and push OK. FX Graph will animate your function by changing a and regraphing the curve.
If you used the settings above, FX Graph would replace a with
-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, -5, -4, -3, -2, -1...
Notice that when FX Graph gets to 5, it starts again at -5. Checking the Reverse box forces FX Graph to animate slightly differently.
-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 4, 3, 2, 1, 0, -1, -2, -3, -4, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 4, 3, 2, 1, ...
Instead of starting again at -5, FX Graph counts down in Reverse, back to -5.
Brain Drain
Animating functions in FX Graph is very computationally intensive because FX Graph has so much to calculate each time. Intercepts, maxima and minima, integrals, derivatives... everything is recalculated. This means that on slower computers, the animations may not be as fast as you would like.
Stopping an Animation
You can stop an animation by left-clicking anywhere on the graph.
Animation with Multiple Constants
If you have more than one constant, you can change the other constants during the animation. Try animating the c constant in y = ax2 + bx + c. While the animation is running, change a and b.