1. Which relation is a function?


(0, 4), (-4, 2), (7, 1), (-8, 2)

(0, 4), (-4, 6), (0, 3), (-8, 2)

(0, 0), (-4, 3), (7, 1), (-4, 5)

(7, 1), (-4, 4), (0, 1), (7, 2)

2. Which relation is a function?

(2, 0), (-3, 3), (9, 1), (-3, 5)

(9, 1), (-3, 4), (2, 1), (9, 2)

(2, 4), (-3, 2), (9, 1), (-7, 2)

(2, 4), (-3, 6), (2, 3), (-7, 2)