Question

Determine which relation is a function.

A.
{(–3, 2), (–2, 3), (–1, 1), (0, 4), (0, 1)}

B.
{(–3, 2), (–1, 3), (–1, 2), (0, 4), (1, 1)}

C.
{(–3, 3), (–2, 3), (–1, 1), (0, 4), (0, 1)}

D.
{(–3, 2), (–2, 3), (–1, 2), (0, 4), (1, 1)}

Answer 1

@mathmate @mathmath333

Answer 2

If the ordered pairs are in a set, then the \(x\)-values should not be repeated.
If they do repeat, then it is a function \(only~if\) the corresponding y-values are identical.
Example:
{(1,2),(2,3)} is a function (x don't repeat)
{(1,2),(1,2),(2,3)} is still a function because the x repeat, but the y are identical, so the two (1,2) are essentially one so there's no repetition.
{(1,2),(1,3),(2,3)} is not a function, because x repeat, by y are different.

Answer 3

Ok

Answer 4

It's making sense