Find the average rate of change of the function over the given intervals. le)=3x3+3; a)l3,5].b)[-1.1l E) a) The average rate of change of the function f(x) = 3x3 + 3 over the interval [3,5] is D. (Simplify your answer.) b) The average rate of change of the function f(x) = 3x3 + 3 over the interval [- 1,1] is D. (Simplify your answer.)