Precalculus problem

Question

Using a graphing calculator, graph f(x)=-x^3+6x^2-9x-9 in the viewing rectangle [-3,7,-20,15]. Find the intervals on which the function is increasing or decreasing and find any relative maxima or minima.

Answer 1

Increasing on (1,3)

decreasing (-infinity,1) U (3,infinity)

relative min (1,-13)

relative max ( 3, -9)