Question

Which sets of ordered pairs represent functions from A = {1, 2, 3, 4} to B = {−1, 0, 1, 2, 3}? Justify.

{(1, 3), (4, 1), (2, 2)}

Answer 1

{(1, 3), (4, 1), (2, 2)} does not represent a function.

Reason:

3 ∈ A does not have an image in set B.