#### Answer

(a) $(-1, 0) \cup (1, +\infty)$
(b) $(-\infty, -1) \cup (0, 1)$
(c) The graph has no interval where its value is constant.

#### Work Step by Step

(a) The graph is rising from $x=-1$ to $x=0$ as well as from $x=1$ to the right. Thus, the function is increasing in the interval $(-1, 0) \cup (1, +\infty)$.
(b) The graph is falling from the left up to $x=-1$ as well as from $x=0$ to $x=1$. Thus, the function is decreasing in the interval $(-\infty, -1) \cup (0, 1)$.
(c) The graph has no interval where its value is constant.