Question

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

{(1, 0), (3, 3), (2, −1), (4, 1), (2, 2)}

Answer 1

{(1, 0), (3, 3), (2, –1), (4, 1), (2, 2)} does not represent a function.

Reason:

(2, –1), (2, 2), show that element 2 ∈ A has been assigned two images –1 and 2 from set B.77