Step 1:

The area of the function is

Graph the function .

Observe the graph:

The graph of the function is the upper part of the circle with radius 7.

The region under the semicircle is the area of the function.

Step 2:

The area of the function is  .

Solution:

Step 1 :

The function is .

Apply derivative on each side with respect to .

.

Graph : \ \

Graph the function .

Observe the Graph :

over the interval .

Therefore the function is increasing over the interval .

over the interval .

Therefore the function is decreasing over the intervals .