Using the Rolle's Theorem and the Mean Value Theorem

a. Given that f(1) = pie and f(3) = pie , use the Mean value theorem to prove that f must have at least one critical point between x=1 and x=3 ( Yes, the Mean value Theorem since f(1) and f(3) are not equal to zero)

b. Explain how rolle's theorem is a specific case of the Mean value theorem