Let f(x) = 8x². Compute f(3 + h). (Use symbolic notation and fractions where needed.) f(3 + h) = 8h² +48h +72 Compute (3+h)-f(3) h (Use symbolic notation and fractions where needed.) f(3+h)-f(3) h = Compute f'(3) by taking the limit as h → 0. (Give your answer as a whole or exact number.) f'(3) =