is $G(x) = |x-2|$ one to one OR onto?

Question

Please help me determine if $G(x) = |x-2|$ is one to one or onto.

Answer 1

HINTS

1. Write down the definitions of from where and to where is $G$ supposed to map. I will assume $G:\mathbb{R} \to \mathbb{R}$ but this is not necessarily true.
2. Onto means $G$ maps to every point of $\mathbb{R}$. Note that $G(x) \ge 0$, what can you conclude?
3. $1-1$ means that $G(x) = G(y)$ if and only if $x = y$. Well, $G(x) = G(y)$ means $|x-2| = |y-2|$. Does it follow that $x=y$?