Is this relation a function {(−1, 7), (9, 4), (3, −2), (5, 3), (9, 1)}? Why or why not?

Answer 1

No, this relation is not a function. A function is a relation where each input (x-value) corresponds to exactly one output (y-value). In this given relation, there are two inputs with the same x-value of 9, but different y-values of 4 and 1. Since the x-value 9 does not correspond to a unique y-value, this relation is not a function.