Lesson objective: Graph a function given a description of the behavior of the function.

This lesson helps to build procedural skill with representing the behavior of a function graphically. Verbal descriptions and graphs are used here because they highlight the connection between these representations. This work develops students' understanding that graphing and understanding input-output relationships can highlight the behavior of a function.

Students engage in Mathematical Practice 2 (reason abstractly and quantitatively), as well as Mathematical Practice 4 (model with mathematics), as they create a model of a function based on the description of the relationship between inputs and outputs of the function.

**Key vocabulary:**

- behavior
- constant
- decreasing
- function
- gradual
- horizontal
- increasing