Question

Find the derivative of f(x) = 12x2 + 8x at x = 9.

a) 256
b) -243
c) 288
d) 224

Answer 1

C) 288

Explanation:

C) 288

F(x) = 12x2 + 8x

F(x) = 12×9×2 + 8(9)

F(x) = 216 + 72

F(x) = 288

Answer 2

224

Explanation:

f(x)f ′(x)f ′(9)=12x2+8x=24x+8=224