The red graph is the f(x), the one you have given and the blue graph is the f ' (x)
x < -3, f ' (x) is decreasing
x = -3, f ' (-3) = 0 (critical point)
-3 < x < 0, f ' (x) is increasing
x = 0, f ' (0) is undefined (critical point)
x > 0, f ' (x) = - 4