Answers to p.176 #3-4

If the graphs represent f(x):
3. f(x) is increasing on (-inf, -2), (2, inf); f(x) is decreasing on (-2, 2); f(x) has critical points at -2 & 2.
4. f(x) is increasing on (-1, 0), (1, inf); f(x) is decreasing on (-inf, -1), (0,1); f(x) has critical points at -1, 0, & 1.

If the graphs represent f '(x):
3. f(x) is increasing on (-3.5, 0), (3.5, inf); f(x) is decreasing on (-inf, -3.5), (0, 3.5); f(x) has critical points at -3.5, 0, & 3.5.
4. f(x) is increasing on (-inf, -1.3), (1.3, inf); f(x) is decreasing on (-1.3, 0), (0, 1.3); f(x) has critical points at -1.3, 0, 1.3.