which of the following input/ output tables define a function?

Question

which of the following input/ output tables define a function?

A)

Input	Output
0	0
0	1
1	2
1	0

B)

Input	Output
0	1
1	2
1	3
1	4

C)

Input	Output
0	2
1	2
1	3
3	3

D)

Input	Output
0	1
1	2
2	3
3	4

Answer 1

A function is a relation where each input has exactly one unique output. That said, in the choices presented above, there are several where the input repeats and has a more than one output. In only one option, do the numbers in the input column not repeat and hence that one would represent a function.