Graphs of $g(x)$ and $f(x)$

Mapping Diagram Showing Composition.
Given a point / number, $x$, on the source line, there is a
blue arrow meeting the target line at the point /
number, $ x^2  2$This point corresponds to the quadratic function's value for $x$. The values for the core mapping diagram for $x2$ in red are applied to the values $g(x)=x^2$ (green) . 