Question

The real part of $6e^{i\pi /3}$ is

• A. 3

Answer 1

The correct option is A 3
$6e^{\frac{i\pi }{3}}=6[cos\frac{\pi }{3}+isin\frac{\pi }{3}]$
$=6cos\frac{\pi }{3}+i\left(6\sin \frac{\pi }{3}\right)$
Real part $=6cos\frac{\pi }{3}=6\times \frac{1}{2}=3$.