For the principal values, evaluate each of the following : `cos^(-1)1/2+2sin^(-1)1/2` (ii) `cos^(-1)(1/2)-2sin^(-1)(-1/2)`

Explanation

`cos^(-1)(1/2)+2sin^(-1)(1/2)`

`=pi/3 +2. pi/6`

`=pi/3 +pi/3`

`=(2pi)/3`

ii)`cos^(-1)(1/2)-2sin^(-1)(-1/2)`

`=pi/3 -2(-pi/6)`

`=pi/3+ pi/3`

`=(2pi)/3`