$\"\"$

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The complex number is $\"\"$ .

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Write the expression into polar form.

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Consider $\"\"$ .

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Multiply and divide by $\"\"$ .

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$\"\"$ .

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

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Here $\"\"$ .

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

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$\"\"$ .

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$\"\"$

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De-Moivre theorem:

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If $\"z$ is complex number then $\"z$ .

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$\"\"$

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$\"\"$ .

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$\"\"$ .

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$\"\"$

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The standard form is $\"\"$ .