# 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)}?

Nov 20, 2015

See explanation.

#### 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 $f \left(x\right) = y$"

This relation is not a function because this condition is not met. Element $x = 5$ has two corresponding values ($8$ and $9$)