Use the sign diagram for f'(x) to determine the following. (If an answer does not exist, enter DNE.) f ( x) - - -0+ + + + + 0 x (a) the critical values of f(x) (Enter your answers as a comma-separated list.) X = (b) intervals on which f(x) increases (Enter your answer using interval notation.) c) intervals on which f(x) decreases (Enter your answer using interval notation.) (d) x-values at which relative maxima occur (Enter your answers as a comma-separated list.) X = (e) x-values at which relative minima occur (Enter your answers as a comma-separated list.) X = Need Help? Read It Watch It # Show My Work (Optional)@