The domain is the set of all x-coordinates and
the range is the set of all y-coordinates.
So the domain for this relation is {0, 1, 2, 3, 4}
and the range is {0, -1, -4, -9, -16}.
Now, I graph these points below.
For the relation tobe a function, it must pass the vertical line test.
If we can draw a vertical line that passes through only one point
anywhere on the graph, the relation is a function.
Notice that if you were to draw a vertical line,
no line would intersect two points on the same line.