12) \ \

\

Step 1: \ \

\

The derivative of the function is $\"\"$ and $\"\"$ .

\

$\"\"$

\

Apply integral on each side.

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

Step 2: \ \

\

Find the value of $\"\"$ .

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$ \ \

\

Substitute $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$ .

\

Solution: \ \

\

$\"\"$ .

\

\

13) \ \

\

Step 1: \ \

\

The derivative of the function is $\"\"$ and $\"\"$ .

\

$\"\"$

\

Apply integral on each side.

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

Step 2: \ \

\

Find the value of $\"\"$ .

\

Substitute $\"\"$ in $\"\"$ .

\

\ \ $\"\"$

\

Substitute $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$ .

\

Solution: \ \

\

$\"\"$ .

\

\

\

\

\ \

\

\

\ \