Answer :
Using the given relations, let's determine the relation which represents a function.
A relation represents a function if for each value of x there is only one possible y-value.
This means that in the relation no value of the x-coordinate must appear twice or be repeated.
Using the relations given, the relation which is a function is:
{(1, 4), (2, 3), (3, 2), (4, 1)}
This is because, in this relation, there is only one value y for each value of x.
In this relation, no x value appears more than once.
Therefore, the relation which is a function is:
{(1, 4), (2, 3), (3, 2), (4, 1)}
ANSWER:
{(1, 4), (2, 3), (3, 2), (4, 1)}