# Lesson 5

More Graphs of Functions

### Lesson Narrative

In this lesson, students begin to analyze graphs of functions and use them to answer questions about a context. Students also look at what happens over intervals of input values and learn that graphs can be viewed as dynamic objects that tell stories.

In the temperature activity, students connect specific features of the graph, such as the highest point, with specific features of the contextual situation, i.e., the highest temperature of the day and when it was attained. In the activity about garbage production, students investigate what happens over ranges of input values. The graph tells us how much garbage was produced at certain times and we can also determine if the amount of garbage was increasing or decreasing over time.

As students learn to interpret graphs in terms of a context and use them to answer questions, they learn an important skill in mathematical modeling (MP4).

### Learning Goals

Teacher Facing

• Describe (orally and in writing) a graph of a function as “increasing” or “decreasing” over an interval, and explain (orally) the reasoning.
• Interpret (orally and in writing) a graph of temperature as a function of time, using language such as “input” and “output”.

### Student Facing

Let’s interpret graphs of functions.

### Student Facing

• I can explain the story told by the graph of a function.