( 1+ +i 1+ -i ) ^ n = - Vidyadip

MCQ

${{\left( \frac{1+\cos \varphi +i\sin \varphi }{1+\cos \varphi -i\sin \varphi } \right)}^{n}}=$

A
$\cos n\varphi -i\sin n\varphi $
✓
$\cos n\varphi +i\sin n\varphi $
C
$\sin n\varphi +i\cos n\varphi $
D
$\sin n\varphi -i\cos n\varphi $

✓

Answer

Correct option: B.

$\cos n\varphi +i\sin n\varphi $

B

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