Domain and Range
Recall the concepts of the domain and range of a relation, as discussed in the previous chapter. The set of all first coordinates of the ordered pairs is called the domain of the relation, while the set of all second coordinates is called the range of the relation.
Example 1
Find the domain and range of the following relation, which is composed of the set of National Basketball Association (NBA) players and their corresponding heights:
{(Kevin Durant, 6'9"), (LeBron James, 6'8"), (Jeremy Lin, 6'3")}.
Solution
The domain of the given set is the set of all first coordinates; that is,
{Kevin Durant, LeBron James, Jeremy Lin}.
The range, which is the set of all second coordinates, is
{6'9", 6'8", 6'3"}.
