Question

determine whether each graph represents a function. select yes or no for each graph.

1. □ yes □ no
2. □ yes □ no
3. □ yes □ no
4. □ yes □ no
5. □ yes □ no

Explanation:

A relation is a function if every input (x-value) has exactly one output (y-value; the vertical line test: no vertical line intersects the graph more than once).

1. First graph: Each x has one y → passes vertical line test.
2. Second graph: Some x-values have two y-values → fails vertical line test.
3. Third graph: Some x-values have two y-values → fails vertical line test.
4. Fourth graph: Each x has one y → passes vertical line test.
5. Fifth graph: Each x has one y → passes vertical line test.

Answer:

1. Yes
2. No
3. No
4. Yes
5. Yes