Determine whether Rolle's Theorem can be applied to f on the closed interval [a, b]. (Select all that apply.) f(x) = cos x, (л, зл] O Yes. O No, because f is not continuous on the closed interval [a, b]. O No, because f is not differentiable in the open interval (a, b). O No, because f(a) + f(b). 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.)