Question 7134
The definition of a function is that for each value in the domain there is only one value in the range; restated: for each value x, there is only one value y which is determined by x.
You have a list of number pairs. Is there any value of x for which there is more than one value of y? If there is, the relationship between the two sets of numbers is not a function. If there isn't, then the relationship is a function.