Verify that the function satisfies the three hypotheses of Rolle's Theorem on the given interval. Then find all numbers "c" that satisfy the conclusion of Rolle's Theorem.

Question

f(x)=sin4pix , [-1/2,1/2]

Well according to Rolle's Theorem, it has to be continuous on [a.b] and it is and differentiable on (a,b) and it is too. Not so sure about f(a)=f(b).

Then I got the derivative = cos(4pix)4pi

I don't know what to do from there on.. Please help!