Question

Let f be the function given by f(x)=5x^3 - 3x - 7. What is the value of f’(-2)?

Answer 1

Answer:

D. 57

Step-by-step explanation

$f(x)=5x^3 - 3x - 7 \\ \\ f'(x) = 5 \times 3 {x}^{2} - 3 \times 1 - 0 \\ \\ f'(x) = 15 {x}^{2} - 3 \\ \\ plug \: x = - 2 \\ f'( - 2) = 15 {( - 2)}^{2} - 3 \\ \\ f'( - 2) = 15 \times 4 - 3 \\ \\f'( - 2) = 60 - 3 \\ \\f'( - 2) = 57$

Answer 2

letter c is the correct answer