Question 9 of 18 1 Points Suppose f(x) = A(x) B(x) and you are told that A(39) = 0, B(39) = -3, A' (39) = 3, B' (39) = -3. Then, f' (39) =Materials Part 8 of 9 - HINT: CHAIN + PRODUCT Quizzes Question 8 of 18 1 Points X If f (x ) = x4(x3 + 9) , determine df dx A. 4x3(x3 + 9)5 + 15x6(x3 + 9)4 O B. 60x3 (x3 + 9)4 O c. 20x'(3x2) 4 OD. 4x (x3 + 9)5 O E. 15x(x3 +9)4 Reset Selection