$\"\"$

\

The differential equation is $\"\"$ .

\

$\"\"$

\

$\"\"$

\

Apply integral on each side.

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

Exponentiate each side.

\

$\"\"$

\

$\"\"$

\

$\"\"$ , where $\"\"$ is a constant.

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

$\"\"$

\

The limit of $\"\"$ is $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

$\"\"$ .

\

$\"\"$

\

$\"\"$ .

\

$\"\"$ .