Which relation is a function?

Question

Here are the answer choice:

A.(8, –4), (8, 4), (6, –3), (6, 3), (0, 0)

B.(4, 7), (8, 5), (6, 4), (5, 3), (4, 2)

C.(0, 0), (1, 1), (2, 2), (3, 3), (4, 7)

D.(0, 0), (1, 0), (1, 1), (2, 1), (1, 2)

Answer 1

In a function, each x-value can only have 1 y-value (not more than one y-value). So for example in part a, notice that the x-value 8 has two different y-values (4 and -4) so part a is not a function. Now see if you can figure out which one is a function. One part is and the other 3 parts are not. Please submit your answer and we can check it or ask another question about it if you get stuck.

Answer 2

C, because no X has more than one y.