Question

Which relation is also a function?

((0,3), (1, 2), (1, 4), (2, 1)]

[(-1, 3), (0, 2), (3, -1), (3, 2))

{(2,-4), (2,-2), (2, 1), (2, 3)]

[(-4,-3), (0, -3), (1, -3), (4, -3)]

Answer 1

4th. as it had UNIQUE values for every x

unlike rest 3,

like 2nd has two values of 3, not a function