Question: A light ray starts at the origin and is reflected off a mirror along the line y = 1 to the point (2, 0). See Figure. Fermat's Principle says that light's path minimizes the time of travel. The speed of light is a constant.
(a) Using Fermat's Principle, find the optimal position of P.
(b) Using your answer to part (a), derive the Law of Reflection, that θ1 = θ2.
