The given graph of the derivative $f'$ of a function $f$ is shown. Answer the following questions only on the interval $(-6,6)$.

1. On what intervals is $f$ increasing?
2. On what intervals is $f$ decreasing?
3. At what values of $x$ does $f$ have a local maximum?
Answer (separate by commas): $x =$
4. At what values of $x$ does $f$ have a local minimum?
Answer (separate by commas): $x =$