Hello christina1 and , so , for all values of .

In fact (can you see why?), so the graph is a horizontal line at for

2 Note that , for all valid values of , and . The derivative takes negative values since decreases from to as increases from to .

Thus, using the Chain Rule, if while is increasing in the range .

Now increases from to as increases from to , so in this range . But for decreases from to , and for decreases from to . Hence in these ranges is increasing, and therefore .

The graph is as shown in the attached diagram.

Grandad