We define a function as a relation that maps elements from one set (domain) into elements of another set (range), where we also have the restriction that each element from the domain can be mapped into only one element from the range.
Knowing this, we can see that our relationship is a function.
How did we conclude that the relation is a function?
If you look at the relation:
{(−10,9),(−6,4),(−9,9),(10,9)}
You will see that for the four points, the domain element (the first value) is different, thus we do not have any problem (We would have a problem if there were two points with the same first value, which would imply that an element from the domain is being mapped into two different values of the range).
Thus, we can conclude that this relation describes a function of x.
If you want to learn more, you can read:
https://brainly.com/question/6241820
