Consider the ray shown bouncing off the bottom of the surface in the preceding problem. Replace the surface at this point by the more highly-curved surface shown in dotted lines. The ray still bounces from \(\mathrm{O}\) to \(\mathrm{I}\). Is the ray now a path of minimum time, maximum time, or is it stationary but of neither minimum nor maximum time? Compare with nearby paths that bounce once but are otherwise straight. Suppose the paths must bounce once but need not be segments of straight lines. What then?