Can someone please help me?
Which of the following relations is a function?

{ (2, 6), (3, 9), (4, 2), (3, 6) }

{ (2, 8), (3, 6), (2, 4), (0, 2) }

{ (3, -2), (4, 7), (-2, 5), (-4, 5) }

{ (4, 7), (-2, 5), (1, 3), (-2, 1) }

Question

Can someone please help me?
Which of the following relations is a function?

    { (2, 6),  (3, 9),  (4, 2),  (3, 6) }

    { (2, 8),  (3, 6),  (2, 4),  (0, 2) }

    { (3, -2),  (4, 7),  (-2, 5),  (-4, 5) }

    { (4, 7),  (-2, 5),  (1, 3),  (-2, 1) }

anonymous · Answer

the one where there is no repeat in the first numbers
check C first it is usually C

igreen · Answer

LOL ^^ Check C xD

igreen · Answer

Functions can only have 1 x-value, so which one should it be?

igreen · Answer

Option A x-values: 2, 3, 4, 3

Option B x-values: 2, 3, 2, 0

Option C x-values: 3, 4, -2, -4

Option D x-values: 4, -2, 1, -2

So which one is it? It should be the one that only has all different x-values.

anonymous · Answer

A? @iGreen

igreen · Answer

No, A has two 3's in it, so it's not a function.

anonymous · Answer

No it's B! @iGreen

igreen · Answer

No, B has two 2's..

2, 3, 2, 0
^      ^

anonymous · Answer

C >.< @iGreen

igreen · Answer

Yes, that's correct. @itsdaniela

anonymous · Answer

Thank you! @iGreen

igreen · Answer

No problem.