My problem, which I proposed to myself months ago is based on the simple optimization problem
in which you find the best path for a lifeguard to rescue a drowning victim. Obviously the
shortest path is a straight line, but the catch is he swims more slowly than he runs. I
solved the problem and then attempted with 3 different speeds (beach, water, and weeds, or
something of the sort). The difficulty didn't set in until I allowed the difficulty of
traversing a point in the plane vary continuously. How do I find an optimal path?