2. Find f'(x).
3. Draw a graph of y = f'(x).
4. Note that m = f'(x) = tan (theta) where theta is the angle between the x-axis's positive direction.
5. Solve tan(0) < f'(x) < tan(45) <=> 0 < f'(x) < 1 (all angle sin degrees). The graph of y = f'(x) might help to see what's happening with this inequation.