Find f'(x) for f(x) = −8x^2 − 5x − 4.

a.) −16x − 5
b.) −16x − 4
c.) 16x + 5
d.) none of these

D/dx of -8x^2 - 5x - 4

So, use the power rule: -8 * d/dx (x^2) this means (x^n)' = n * x^n-1

So -8*2x

-5 * d/dx (x) = -5 * 1

So -5

d/dx of 4 is 0, because 4 is a costant.

Final result

-16x - 5