Relation: A relation is simply a set of ordered pairs.
The first elements in the ordered pairs, the xvalues, form the domain. The second elements in the ordered pairs, the yvalues, form the range.
This mapping shows a relation from set A into set B. The relation consists of the ordered pairs
(1,2), (1,3), (4,6), (5,6), and (7,8).
The domain is the set {1, 4, 5, 7}
The range is the set {2, 3, 6, 8}.
The range is the dependent variable.
Function:
A function is a set of ordered pairs in which each element of the domain has only ONE element associated with it in the range.
The relation shown above is NOT a function because the element 1 (in the domain) is mapped to two elements in the range, 2 and 3.
A function may have two xvalues assigned to the same yvalue, but may not have two yvalues assigned to the same xvalue.
Example
Domain = {1,4,5,7}
Range = {2,3,6,8}
Relation = {(1,2), (4,3), (5,6), (7,8)}
This relation is a function.
Directions: Answer the following. Enclose the answer in curly brackets { }. Also write at least 5 examples of your own.
