Is (-4,1), (1,-8), (-2,-2) a function?
(-4,1), (1, -9) and (-2,-2) are just three distinct points.
They are not a function as such, but they could be used to define a function.
Yes, the set
A function is a set of ordered pairs in which no two pairs have the same first element and different second elements.
This definition, in a way, tells us how a collection of ordered pairs call fail to be a function.
The set you asked about has no two pairs with equal first and different second elements. So it is a function.