Answer
The projection of a point $(a,b)$ onto the x-axis is the point $(a,0).$
The graph of a function contains points $(x,f(x))$,
and its projection onto the x-axis includes points $(x,0)$ where $x$ is from the domain of f.
Since all points on the x-axis have second coordinate 0,
we can loosely say that the domain of f is projected onto the x-axis.
"Loosely" is used because the x-axis contains ordered pairs,
and the domain contains numbers
(that happen to be the first coordinates of those ordered pairs)
Work Step by Step
No steps, as the answer contains a discussion.
