$\"\"$

\

The statement is $\"\"$ .

\

Euler $\"\"$ s Formula:

\

For any real number $\"\"$ , $\"\"$ .

\

$\"\"$ .

\

Find $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

$\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$ , for any real number of $\"\"$ .

\

$\"\"$

\

$\"\"$ , for any real number of $\"\"$ .