# Lesson 15

Finding Input Values and Function Values

These materials, when encountered before Algebra 1, Unit 4, Lesson 15 support success in that lesson.

### Lesson Narrative

In this lesson students use a situation and a graph to find outputs for given inputs and inputs for given outputs. In the associated Algebra 1 lesson students begin examining inverse functions. Students are supported by having a concrete example to think about how to find a particular input for a given output.

Students must look for and express regularity in repeated reasoning (MP8) when they find inputs to match given outputs of a function.

### Learning Goals

Teacher Facing

- Given either an input or output of a function, find the other.

### Student Facing

- Let’s play with inputs and outputs of functions.

### CCSS Standards

Building Towards