Anyway, I've come across this problem that I can't figure out. It looks set up as a Rolle's Thm problem, but it just doesn't work out... Let f be a continuous function on [a,b] and differentiable on (a,b) for some a,b > 0. Suppose f(a) = f(b) = 0. Show that f'(c)=f(c)/c for some c between a and b. The thing is this is next to straightforward problems like the integral of xsinx and |3-2x|>1. Am I just missing something? I mean, I've spent about 3 hours looking for a similar problem/theorem in my Calc book; even just a pointer from someone who knows the answer would be great.