Relations and Functions

Students learn that a relation is a set of ordered pairs. For example, {(-4,10), (6, 0), (9, -7)} is a relation. The domain of a relation is the set of all x-coordinates of the relation. So in the relation above, the domain is {-4, 6, 9}. The range of a relation is the set of all y-coordinates of the relation. So in the relation above, the range is {10, 0, -7}. Students also learn that if the x-coordinate is different in each ordered pair in a given relation, then the relation is a function. Finally, students use the vertical line test to determine if the graph of a relation is a function.
category:functions