Function Or Not?
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.