There are a couple correct answers. There is the cheesy one where you just let f(x) = root((1/x) + 2) .... (i.e. the whole thing) and let g(x) = x ... (the identity).
But most teachers would not appreciate the beauty of that answer.
You could also consider the "root" to be one function, and everything else to be the other. So g(x) is what's inside the root...
g(x) = 1/x + 2
f(x) = root(x)
g(x) = 1/x
f(x) = root(x + 2)