### Home > CC3 > Chapter 9 > Lesson 9.1.1 > Problem 9-13

9-13.

Determine whether the graphs below are functions or not functions. Explain your reasoning.

A graph is only a function if there is no more than one -value for any given

*-value.*

Are there any points on this line segment that are above or below another point on the line segment? If there are, the graph is not a function.

This graph is a function.

See hint for part (a).

This graph is not a function. Some

-values are related to multiplevalues. For example, whenis, can beor .

See hint for part (a).

See hint for part (a).

See hint for part (a).

This graph is not a function.

See hint for part (a).