$\"\"$

\

a.

\

Find the interval of possible angles of the ball needed to clear the net.

\

The function $\"\"$ .

\

Here, $\"\"$ feet and $\"\"$ feet/sec.

\

Substitute the corresponding values in $\"\"$ .

\

$\"\"$

\

The sine function is also positive in Quadrant II.

\

So, $\"\"$ .

\

$\"\"$

\

Therefore, the possible angle of the ball needed to clear the net is $\"\"$ or $\"\"$ .

\

Hence the possible interval is $\"\"$ . $\"\"$

\

b.

\

Consider $\"\"$ .

\

Substitute $\"\"$ feet and $\"\"$ feet/sec in $\"\"$ .

\

$\"\"$

\

The sine function is also positive in Quadrant II.

\

So, $\"\"$ .

\

$\"\"$

\

Therefore, the possible angle of the ball needed to clear the net is $\"\"$ or $\"\"$ .

\

$\"\"$

\

a.The possible interval is $\"\"$ .

\

b. The possible angle of the ball needed to clear the net is $\"\"$ or $\"\"$ .