Question

Find the value of the following: `cos^(-1)(cos((13pi)/6))`

Answer 1

`cos^-1(cos13pi/6)` can be written as
`cos^-1(cos(2pi+pi/6))`
As, `cos(2pi +x) = cos x`, So, our expression becomes
`=cos^-1(cos(pi/6)) = pi/6`