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