# How do you find the value of sec^-1[(2sqrt 3)/3]?

Ans: $\frac{\pi}{6} \mathmr{and} \frac{5 \pi}{6}$
$\cos x = \frac{3}{2 \sqrt{3}} = \frac{\sqrt{3}}{2}$ --> arc $x = \pm \frac{\pi}{6}$
Ans: $x = \frac{\pi}{6}$ and $x = \frac{5 \pi}{6}$