Determine whether Rolle's Theorem can be applied to f on the closed interval [a,b]. (Select all that apply.)
f (x) = sin(x), [0, 2π]
If Rolle's Theorem can be applied, find all values of c in the open interval (a, b) such that f '(c) = 0. (Enter your answers as a comma-separated list. If Rolle's Theorem cannot be applied, enter NA.)
I thought the derivative would be cos(x) so then cos(0) would be 1 but thatz wrong so now I don't understand how to do this!