# Vertical Line Test

## Topic

Functions and Relations

## Definition

The vertical line test is a method used to determine if a graph represents a function by checking if any vertical line intersects the graph more than once.

## Description

The vertical line test is important in mathematics because it helps in identifying whether a given graph represents a function. If a vertical line intersects the graph at more than one point, then the graph does not represent a function. This test is used in various fields, including computer science for validating functions in programming and in mathematics for analyzing graphs. For example, the graph of

y = x2

passes the vertical line test, indicating it is a function, while the graph of a circle does not. Understanding the vertical line test is essential for analyzing and interpreting graphs in mathematical and real-world contexts.

For a complete collection of terms related to functions and relations click on this link: Functions and Relations Collection

Common Core Standards CCSS.MATH.CONTENT.8.F.A.1, CCSS.MATH.CONTENT.8.F.B.5, CCSS.MATH.CONTENT.HSF.IF.A.1, CCSS.MATH.CONTENT.HSF.IF.A.2, CCSS.MATH.CONTENT.HSF.IF.C.7, CCSS.MATH.CONTENT.HSF.BF.A.1, CCSS.MATH.CONTENT.HSF.BF.B.3, CCSS.MATH.CONTENT.HSF.BF.B.4 6 - 9 Algebra     • Functions and Relations         • Relations and Functions 2013 definition, function, relations, glossary terms