How do you find the domain and the range of the relation, and state whether or not the relation is a function {(4, –6), (3, –6), (–2, 5), (4, 1)}?

1 Answer
Shantelle
Aug 2, 2018

Domain : #-{2, 3, 4}#

Range : #{-6, 1, 5}#

Not a function.

Explanation:

The domain is also known as the #x#-values and the range is the #y#-values.

Since we know that a coordinate is written in the form #(x, y)#, all the #x#-values are:
#{4, 3, -2, 4}#

However, when we write a domain, we typically put the values from least to greatest and do not repeat numbers. Therefore, the domain is:
#-{2, 3, 4}#

All the #y#-values are:
#{-6, -6, 5, 1}#

Again, put them in least to greatest and do not repeat numbers:
#{-6, 1, 5}#

In a function, each #x-#value can only pair with one #y#-value (each input has a single output). Since there are two "#4#"s in the #x#-values, there are two same #x#-values paired with two different #y#-values, so this relation is not a function.

Hope this helps!

Related questions
See all questions in Domain and Range of a Function
Impact of this question
1209 views around the world
You can reuse this answer
Creative Commons License