Is there a way to find $\sqrt[n]{x}$ with `Mathematica` beside of `x^(1/n)`
as this is something different, because this is not always the same
$$(-1)^{\frac{2}{4}}=i \neq 1= \sqrt[4]{(-1)^2}$$
In the help I only found `Sqrt[x]` which is the squareroot and `CubeRoot[x]` for the cubic root.  
Is there a reason that there aren't $n$-th roots implemented? (Assuming they really don't exist and I am not to stupid to find them).

I am using `Mathematica 9.0.1 Student Edition`