- The relation in the top-left graph is not a function because it fails the vertical line test; there are x-values (like x=0) that correspond to multiple y-values.
- The relation in the top-right graph is not a function because it fails the vertical line test; there are vertical lines that intersect the curve at more than one point.
- The relation in the bottom-left graph (a circle) is not a function because it fails the vertical line test; any vertical line drawn through the interior of the circle intersects it at two points.
- The relation in the bottom-right graph is a function because it passes the vertical line test; every vertical line intersects the graph at most once.
Parent Tip: Review the logic above to help your child master the concept of functions vertical line test worksheet.
