$\"\"$

The expression is $\"\"$ .

Write the expression into polar form.

Consider $\"\"$ .

Multiply and divide by $\"\"$ .

$\"\"$ .

Compare the complex number inside the expresion $\"\"$ with $\"\"$ .

Here $\"\"$ .

Angle satisfies both the conditions is $\"\"$ .

$\"\"$ .

$\"\"$

De Moivre theorem: if $\"z$ is complex number, then $\"z$ .

$\"\"$

$\"\"$ .

$\"\"$

The standard form is $\"\"$ .