help? derivatives-shape of graph?

Question

Answer 1

(3)

Step 1:

Increasing / Decreasing test :

If on the interval, then f  is increasing on the interval.

If on the interval, then f  is decreasing on the interval.

Observe the graph .

over the intervals and , therefore the function is increasing on the intervals and .

over the interval , therefore the function is decreasing on the interval .

Solution :

The function is increasing over the intervals and .

The function is decreasing over the interval .

Answer 2

(4)

Step 1:

Increasing / Decreasing test :

If on the interval, then f  is increasing on the interval.

If on the interval, then f  is decreasing on the interval.

Observe the graph .

over the interval , therefore the function is decreasing on the interval .

Solution :

The function is decreasing over the interval .