I can’t tell from your question alone — please upload the graph or describe the relations (shapes or points).
Explanation
To decide which graphed relation is a function, use the vertical line test: a graph represents a function if and only if no vertical line intersects the graph in more than one point. For discrete points, the relation is a function when each x-value appears at most once.
Quick steps you can use
- Draw or imagine vertical lines across the whole graph.
- If any vertical line hits the graph more than once, that graph is NOT a function.
- If every vertical line hits at most one point, it IS a function.
Common examples
- A parabola opening up or down — passes (is a function).
- A vertical line — fails (not a function).
- A circle — fails (vertical lines cross twice unless tangent).
- A straight non-vertical line — passes (is a function).
- A set of points — check for repeated x-values.
Upload the graph or describe each option (e.g., “A: circle centered at (0,0), B: line y=2x, C: two points (1,2) and (1,3)…”), and I’ll tell you which is a function and why.