Question
Derive the Law of Reflection, $\theta_{i}=\theta_{r}$, by using the calculus to minimize the transit time, as required by Fermat's Principle.
Step 1
After reflection, the ray is going to point P. Let the distance between S and P be A. Draw a normal at point B, and let this point be N. If the distance SN is X, then the distance NP is A - X. The distance between B and N is H. Show more…
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