What is the domain of $f(x)=x^{2/4}$ What is the domain of $f(x)=x^{2/4}$
Is $f(x)= (\sqrt[4]x)^2 $ with $\operatorname{dom} (f)  = [0,\infty) $ 
or $\sqrt[4]{x^2}$ with $\operatorname{dom} (f) = (-\infty,\infty)$ 
or is $f(x)=\sqrt x$ with $\operatorname{dom} (f)=[0,\infty)$
I have tried searching the internet but couldn't find anything.

since $$x^{2/4}=x^{1/2}$$ we have $$x\geq 0$$
