Given:
The graph of a relations.
To find:
Whether the relation is a function or not.
Solution:
A relation is a function if there exist unique outputs for each input. If a graph passes the vertical line test then is a function.
Vertical line test: Each vertical line intersect the curve at most one.
In the given figure draw a vertical at
as shown in the below figure.
From the below graph, it is clear that the vertical line intersects the curve at two points. So, it does not pass the vertical line test.
Therefore, the given relation is not a function.