nataleighledford13 nataleighledford13 17-12-2021 Mathematics contestada Which relation is a function? {(1, 4), (2, 3), (3, 2), (4, 1)} {(4, 2), (3, 3), (2, 4), (3, 2)} {(1, −1), (−2, 2), (−1, 2), (1, −2)} {(1, 2), (2, 3), (3, 2), (2, 1)}