Use the sign diagram for f (x) to determine the following. (If an answer does not exist, enter DINE.) + + (a) the critical values of ((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