## Explorations
75. Mirrors In the figure, a light ray shining from point A to point P on the mirror will bounce to point B in such a way that the angle of incidence α will equal the angle of reflection β. This is the law of reflection derived from physical experiments. Both angles are measured from the normal line, which is perpendicular to the mirror at the point of reflection P. If A is 2 m farther from the mirror than is B, and if α=30∘ and AP=5m, what is the length PB ?
76. Pool On the pool table shown in the figure, where along the portion CD of the railing should you direct ball A so that it will bounce off CD and strike ball B ? Assume that A obeys the law of reflection relative to rail CD.
