The given graph of the derivative $f'$ of a function $f$ is shown. Assuming the graphs continue in the same way as $x$ goes to infinity and negative infinity, answer the following questions.

---

1. On what intervals is $f$ increasing?
Answer (in interval notation):

2. On what intervals is $f$ decreasing?
Answer (in interval notation):

---

Note: You can click on the graph to enlarge the image.

---