Question

which graph represents a function? graph a graph b graph c graph d

Explanation:

A relation is a function if every input (x-value) has exactly one output (y-value). This is verified using the vertical line test: a vertical line drawn anywhere on the graph will intersect the graph at most once.

• Graph A: Has an x-value with two different y-values (fails vertical line test).
• Graph B: Has an x-value with two different y-values (fails vertical line test).
• Graph C: Every x-value has only one y-value (passes vertical line test).
• Graph D: Has an x-value with two different y-values (fails vertical line test).

Answer:

C. Graph C