Question

How do you find the exact value of `cos^-1(sinpi)`?

Answer 1

`-pi/2`

Explanation:

Use `sin a = cos (pi/2-a).and f^(-1)f(x)=x`.

Here, the given expression is

`cos^(-1)(sin pi)`

`=cos^(-1)(cos(pi/2-pi))`

`=pi/2-pi`

`=-pi/2`