Question

how did you manage to solve ps3's second problem? i've found the derivative but i can't figure out how to demonstrate that the lenght of the tangent is 1

Answer 1

There is no obvious approach, but this way is as straight-foward as I can find.

Answer 2

OK, here is another approach. In retrospect, it's a nice clean approach, but it took some "playing around" to find it.