Question

cos-1($\frac{1}{2}$) + 2 sin-1($\frac{1}{2}$)

Answer 1

cos-1($\frac{1}{2}$) + 2 sin-1($\frac{1}{2}$)

Now, cos-1($\frac{1}{2}$) = $\frac{\pi }{3}$

and sin-1($\frac{1}{2}$) = $\frac{\pi }{6}$

∴ cos-1($\frac{1}{2}$) + 2 sin-1($\frac{1}{2}$)

= $\frac{\pi }{3}$ + 2 x $\frac{\pi }{6}$ = $\frac{2\pi }{3}$.