$2 \cos \theta-1=0$ হলে $\theta=\text { ? }$

$2 n \pi \pm \frac{\pi}{6}$

$\mathrm{n} \pi \pm \frac{\pi}{6}$

$\mathrm{n} \pi \pm \frac{\pi}{3}$

$2 \mathrm{n} \pi \pm \frac{\pi}{3}$