Question

Which of the following relations is a function?

A.
(-9, 2), (-4, 3), (5, 7), (9, 2)
B.
(9, -10), (-9, 7), (9, 6), (-9, 12)
C.
(-9, 0), (-4, 5), (-9, -3), (5, 9)
D.
(-4, -2), (-9, -5), (5, 8), (5, 2)

Answer 1

A.

Explanation:

There can only be one y-value for each x-value. For example: B could not be a function because (9,6) and (9, -10) share an x-value. This would be a relation, but not a function. The correct answer is A.