Question

Question #e0a76

Answer 1

The value is `x`. See explanation.

Explanation:

`tan^{-1}x` is an inverse function of `tanx`, and for any function `f(x)` and its inverse `f^{-1}(x)` we have:

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

So the value of this expression is `x` for every `x` in the domain
`D=RR - {pi/2+kpi;k in ZZ}`