Explanation
We are required to determine if the given graph shows a relation that is a function using a vertical line test:
This is achieved thus:
We know that if a vertical line intersects a curve on an xy-plane more than once then for one value of x the curve has more than one value of y, and so, the curve does not represent a function. If all vertical lines intersect a curve at most once then the curve represents a function.
Therefore, we have:
This graph shows multiple values of y for a value of x. '
Hence, it is not a function.
