Is the following relation a function? x y 1 -2 2 -3 3 1 3 -2

Given relation is NOT a function

A relation is said to be a function if no value in its domain is paired up with more than one value in its range.

Since x values represent the Domain of a relation and y values represent the Range of a relation, in terms of x and y we can say:

A relation is said to be a function if an x-value is not paired up with more than one y-value.

From the above table we can see that the value 3 in x column(Domain) is paired with more than 1 y-values. So the given relation is not a function. 

Are the input values unique, or are there duplications?
If unique:  function
If not unique:  not a function