Let f(x) = 1 - x(2/3), f(-1) = f(1), but there is no number c in (-1, 1) such that f'(c) = 0. Explain why this doesn't contradict Rolle's Theorem.
a. The function is not continuous
b. The function is not differentiable
c. Rolle's Theorem does not apply to cubic functions
d. There is no contradiction; it is consistent with Rolle's Theorem