applying the vertical line test\nwhich graph represents a function?

Explanation:

Step1: Recall vertical - line test

A graph represents a function if any vertical line intersects the graph at most once.

Step2: Analyze first graph

A vertical line will intersect the first graph (a vertical line) infinitely many times. So it's not a function.

Step3: Analyze second graph

There are vertical lines that will intersect the second graph at two points. So it's not a function.

Step4: Analyze third graph

For any vertical line drawn on the third graph, it will intersect the graph at most once. So it is a function.

Step5: Analyze fourth graph

A vertical line will intersect the fourth graph (a horizontal line) infinitely many times. So it's not a function.

Answer:

The third graph represents a function.