Question

Which relation is a function?
{(5, 1), (4, 9), (6, 10)}

{(0, 3), (0, 9), (12, 4)}

{(5, 5), (5, 9), (5, 15)}

{2, 10), (6, 10), (2, 3)}

the third one?

Answer 1

The First one, because you can't have the first number in the set repeat.

In the second choice 0 repeats twice as the first number in the set (the input)

In the third choice 5 repeats twice as the first number in the set

In the fourth choice 2 repeats twice as the first number in the set.

So the correct answer should be A!

Hope this helps!!