Author:
Kate Sidlo

At the end of this tutorial students should be able to use the vertical line test to test if a graph is a function.

Students should be able to explain why the vertical line test works using the definition of a function and/or the code example.

In this tutorial students are introduced to the concept of the vertical line test and how to check if a graph is a function.

The metaphor of a coding grid as a good and bad code as well as good and bad functions is used throughout.

Tutorial

1) Take notes from the podcast

2) Add new definitions from the vocabulary section to your vocabulary sheet

**FUNCTION:** A relationship where every input has one and only one output

**INPUT:** A term or number that is plugged into a relationship; the x-variable in an ordered pair

**RELATIONSHIP:** A comparison of terms, variables, and/or numbers (typically an equation or inequality)

**OUTPUT:** A term or number that is the answer or solution to a relationship; the y-variable in an ordered pair

**VERTICAL LINE TEST:** A test that uses vertical lines to check if a graph is a function. Each vertical line can intersect a graph only once for a graph to be a function.