Hi.

If:

$\displaystyle f:R\rightarrow R,\;f(x)=x^2-4$

and

$\displaystyle g:R+\cup\left\{0\right\}\rightarrow R,\;g(x)=\sqrt x$

Then what is the range of $\displaystyle f\circ g$ and why?

And what's the latex command for the little + symbol that normally goes next to R in the domain?

Thanks for your help.