Formalizing Relations and Functions

How Can You Tell if a Relation is Not a Function?

Every function is a relation, but not every relation is a function! Watch this video to learn how to tell which relations are functions and which are not.
What's the Vertical Line Test?

Even graphs need to worry about tests! Using the vertical line test, you can figure out if a graph is a function or not. Watch this tutorial and learn about the vertical line test. Then, put your graphs to the test!