From point P, a red billiard ball is shot along the indicated path. Here, d is the distance of the ball from the upper boundary of the billiard table.

(a) Click on the check box "graphical representation" in the right graphics window and play the animation. What is displayed in the coordinate system? [br][br](b) When has the distance its greatest value, when its smallest? How can you read this off the graphical representation?[br][br](c) Compare the graphical representation with your own conjecture (see Billiard 1, task (c)). Is your solution correct? Why not?