Q63 / 160 · AP EAMCET 2007 · Mathematics
A value of $n$ such that $\left(\frac{\sqrt{3}}{2}+\frac{i}{2}\right)^n=1$ is
- Correct answerA$12$
- B$3$
- C$2$
- D$1$
Solution
Given,
$\begin{aligned} & \left(\frac{\sqrt{3}}{2}+\frac{i}{2}\right)^n=1 \\ & \left(\operatorname{cis} \frac{\pi}{6}\right)^n=1\end{aligned}$
$\therefore$ Only $n=12$ satisfies this equation.
Hence, the correct answer is option: 'A'.