$\"\"$

\

Continuous income flow $\"\"$ .

\

Annual interest rate is $\"\"$ and time $\"\"$ .

\

Find the present value of the amount.

\

Present value $\"\"$ .

\

Substitute corresponding values in the formula.

\

$\"\"$

\

$\"\"$

\

Consider $\"\"$ .

\

Solve the integral using integration by parts.

\

Formula for integration by parts: $\"\"$ .

\

Here $\"\"$ and $\"\"$ .

\

Consider $\"\"$ .

\

Apply derivative on each side with respect to $\"\"$ .

\

$\"\"$

\

Consider $\"\"$ .

\

Apply integral on each side.

\

$\"\"$

\

Substitute corresponding values in integration by parts formula.

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

Substitute above result in (1).

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

Present value is $\"\"$ .

\

$\"\"$

\

Present value is $\"\"$ .