Increasing and Decreasing Functions

f is increasing on interval if f'(x) > 0 for all x in interval. f is decreasing if f'(x) < 0. f is constant if f'(x) = 0. Critical points: where f'(x) = 0 or undefined. Method: find f'(x), set = 0, find critical points, check sign of f'(x) in each interval.