Question

How do you evaluate `cos^-1(1/2)`?

Answer 1

`cos^-1 (1/2)=+-pi/3+-2pi*n" "`where `n=0, 1, 2, 3,....`

Explanation:

`cos (pi/3)=1/2` and also
`cos (-pi/3)=1/2`

All co-terminal angles with `pi/3` and `-pi/3` have cosine function value`=1/2`

God bless ....I hope the explanation is useful.