Question

Which of the following relations is a function?
Answer

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

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

{(1, 2), (5, 6), (3, 2), (6, 4)}

{(1, 2), (0, 3), (1, 3), (0, 2)}

Answer 1

the third one.

Answer 2

You can tell which one it is because if it is a function, no two ordered pairs have the same first number.

Answer 3

So #4

Answer 4

In #4, (1, 2) and (1 ,3) have the same first numbers.