Question

Is {(–2, 0), (–1, 3), (0, –2), (3, –1)} a function?

Answer 1

Yes: a relation is a function if for each x-value there is exactly one y-value

Answer 2

the definition of a function is that the domain, or x, has exactly 1 image. though the range, or y, may have more than 1 domain, the domain may not have more than 1 image. so yes, it is a function