Recall the following definitions:
A relation is a correspondence between 2 sets.
Algebraically, you can think of a relation as a set of ordered pairs (x,y).
Once special type of relation is called a FUNCTION.
Every function is a relation, but not every relation is a function.
A function is a relation for which each and every input gets mapped to ONE and ONLY ONE output.
The following applets help further illustrate this concept for functions represented graphically.
This relation is NOT A FUNCTION. Slide to see why.
