A function is a relationship between two variables in which the value for one variable determines the value for a second variable. The variable that provides the input for the function is called the independent variable, and the variable that results from the function is called the dependent variable. Functions are also special relationships in that each input value, or domain element, can only generate one output value, or range element. This predictive nature of functional relationships is very important.

You will need to remember a lot of vocabulary when working with functional relationships. To start this lesson, let’s review some of the important terms using the interactive below.