Answer
increases: $none$.
decreases: $(-\infty,0)U(0,\infty)$.
is contant: $none$.
Work Step by Step
Step 1. Graph the function as shown in the figure.
Step 2. Open interval where the function increases: $none$.
Step 3. Open interval where the function decreases: $(-\infty,0)U(0,\infty)$.
Step 4. Open interval where the function is contant: $none$.