is {(0, 20), (2, 70), (10, 45), (1, 30), (3, 70)} a function?

Answer 1

Yes, the set {(0, 20), (2, 70), (10, 45), (1, 30), (3, 70)} is a function. In a function, each input (or x-value) is mapped to exactly one output (or y-value). In this set, each x-value (0, 2, 10, 1, 3) corresponds to exactly one y-value (20, 70, 45, 30, 70).