Question

How do you evaluate `sin^-1(sin((7pi)/10))`?

Answer 1

`(7pi)/10`

Explanation:

Recall that `sin^-1(x)` is the inverse of `sin(x)`

Recall that a composition of inverse functions returns the independent variable.

`f^-1(f(x))=x`

So, if `f(x)=sin((7pi)/10)` and `f^-1(x)=sin^-1(f(x))`

then `f^-1(f(x))=sin^-1(sin((7pi)/10))=(7pi)/10`