Which relation is a function?
Select all that apply.
Responses
{(2, 1), (2,3), (3, 4), (4,5)} {(2, 1), (2,3), (3, 4), (4,5)}
{(2, 1), (−2,1), (3, 2), (4,2)} {(2, 1), (−2,1), (3, 2), (4,2)}
{(−1, 2), (−2,2), (−3, 2), (−4,2)} {(−1, 2), (−2,2), (−3, 2), (−4,2)}
{(2, 1), (2,3), (−2, 5), (−2,7)} {(2, 1), (2,3), (−2, 5), (−2,7)}
{(2, 2), (3,3), (4, 4), (5,5)}
