So let $C(\mathbb{R}_+)$ be all the continuous functions in $[0,\infty)$,
I have the metric space
$(C(\mathbb{R}_+),d) \to (C(\mathbb{R}_+),d)$
I have taken $f,g \in (C(\mathbb{R}_+),d)$
And i want to prove that $0<\frac {1}{\sqrt{2+f(x)}+\sqrt{2+g(x)}}<1$
Question : If not mistaken $f,g \in (C(\mathbb{R}_+),d)$ means that f,g are function with their starting points at $[0,\infty)$ not having a clue about their image/mapping, therefore is there a way to prove the thing I want?