Question

which graph shows a function?

Explanation:

Step1: Recall vertical line test rule

A graph represents a function if no vertical line intersects it more than once.

Step2: Test top-left graph

Vertical lines intersect at most one segment.

Step3: Test top-right graph

A vertical line (e.g., $x=1$) intersects the graph twice.

Step4: Test bottom-left graph

A vertical line (e.g., $x=-3$) intersects the graph twice.

Step5: Test bottom-right graph

All vertical lines intersect the graph exactly once.

Answer:

The bottom-right graph (the straight diagonal line passing through the second and fourth quadrants) is the graph of a function.