8. Find the critical points for the function f(x) = 12x - x3 a. (2, 16) and (-2, -16) c. (2, -16) and (0, 0) b. (0, 0) and (1, 2) d. (2, 16) and (1, 11) - 9. Find the critical point for the function f(x) = x(x - 6). a. (-3, 27) C. (6, 0) b. (0, 0) d. (3, -9) - 10. Find f"(x) if f(x) = Nx. a. C. 272 X X b. - 72 d. 1 -2x X 2