Question

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

Answer 1

Using the power rule, f'(x) =-24x+9. Now plug in 6 into the equation.

Answer 2

so -135?

Answer 3

Yup. Good job.

Answer 4

so what would this be...
Find the derivative of f(x) = 5x + 9 at x = 2.

Answer 5

9?

Answer 6

It would be 10. Do you know how to do the power rule to find the derivative?

Answer 7

do what is it

Answer 8

wait it wouldn't be ten

Answer 9

Oh yeah I thought it was x^2. My fault.

Answer 10

you are left with only a constant in that instance.

Answer 11

It would be 5.

Answer 12

i think you need to solve using the limit definition.

Answer 13

okay yea

Answer 14

because the point x on the derivative, then the original function will be different.

Answer 15

okay thankyou :)