Question

Find the derivative of f(x) = -12x2 + 9x at x = 6

Answer 1

Do I plug in for x

Answer 2

d/dx = -24 x + 9
Plug in x = 6 you got -135

Answer 3

Plug in after you take the derivative

Answer 4

how do I take the derivative?

Answer 5

\[\frac{ d }{ dx } f(x) = n * x ^{n-1}\]. That's the simplest definition. In your cause move 2 down and multiply with -12.
then on the exponential part subtract 1 from 2. You have (2) (-12) x^ (2-1), which equates to -24x

Answer 6

as for 9x, think of it as 9x^1. So (1)(9) x^(1-0) = 9

Answer 7

thank you