Question

Given A = {(1, 3)(-1, 5}(6, 4)}, B = {(2, 0)(4, 6)(-4, 5)(0, 0)} and C = {(1, 1)(0, 2)(0, 3)(0, 4)(-3, 5)}, answer the following multiple choice question:

From the list of sets A, B, and C above, choose the set of relations that correctly represents a function.

Set A only
Sets A and C only
Sets A and B only

Answer 1

So each point is like \((x,y)\).

Answer 2

You can't have two \(y\)s with the same \(x\), because that would mean one input has two outputs.

Answer 3

So any relation which have two points with the same \(x\) is not a function.