How do you find the domain and the range of the relation, and state whether or not the relation is a function {(–2, 4), (5, 8), (3, 6), (5, 9)}?

Question

Isaiah Anthony · Accepted Answer

See explanation.

If the relation is given as set of pairs, then: Domain is the set of all first elements of pairs. In this case it is: #D={-2;3;5}# Range is the set of all second numbers. In this case: #R={4;6;8;9}# To check if this relation is a function you need to check the following condition: "For every element #x# in the domain, there exists one and only one element #y# in range that #f(x)=y#" This relation is not a function because this condition is not met. Element #x=5# has two corresponding values (#8# and #9#)

Julia Adams · Answer

undefined To find the domain and range of the relation and determine if it's a function:

Domain: The set of all x-values in the relation.
Range: The set of all y-values in the relation.
A relation is a function if each input (x-value) is associated with exactly one output (y-value).

Domain: {-2, 5, 3}
Range: {4, 8, 6, 9}
Since the x-value 5 is associated with two different y-values (8 and 9), the relation is not a function.