Lesson objective: Describe the behavior of a function given a graph or table of values.

This lesson helps to build fluency with describing function behavior. Graphs and tables of values are used here because they support the understanding that representations of functions are equivalent and can all highlight important behaviors of the function. This work develops students' understanding that graphing input-output pairs allows us to describe the behavior of the function qualitatively.

Students engage in Mathematical Practice 2 (reasoning abstractly and quantitatively), as well as Mathematical Practice 4 (model with mathematics), as they work between representations to understand the relationship between inputs and outputs in order to describe the behavior of a function.

**Key vocabulary:**

- behavior
- constant
- increasing
- decreasing
- function
- linear