You must put parentheses around those ordered pairs, like this:

(-3,4)   (-1,2)   (0,1)   (1,-1)

It is wrong not to put parentheses around them.

Here is the graph of the function which is the set
of these four ordered pairs.

{(-3,4), (-1,2), (0,1), (1,-1)}



Some functions consist of lines, some of curves, and some of 
just dots like this one.  But functions NEVER contain two points 
where one is vertically above the other.

Edwin