Classify the critical points as relative maxima relative

Question

For each function in Problem.

(a) Find y' = f'(x).

(b) Find the critical values.

(c) Find the critical points.

(d) Find intervals of x-values where the function is increasing and where it is decreasing.

(e) Classify the critical points as relative maxima, relative minima, or horizontal points of inflection. In each case, you may check your conclusions with a graphing utility y = x² + 4x.