CPM Homework Help : CALC Problem 3-180

Let $f$ be the function given by $f(x) = x^3-3x^2-24x + k$ where $k$ is a constant. On what intervals is $f$ increasing?

Hint 1:

$f(x)$ increases when $f^\prime(x) > 0$ .

Hint 2:

Refer to the hints in problem 3-149 for more guidance.