Question

Which relation is also a function?

{(0, 3), (1, 2), (1, 4), (2, 1)}
{(-1, 3), (0, 2), (3, -1), (3, 2)}
{(2, -4), (2, -2), (2, 1), (2, 3)}
{(-4, -3), (0, -3), (1, -3), (4, -3)}

Answer 1

Answer: Last option.

Explanation:

By definition, a relation is a function if each input value (value of "x") has one and only one output value ( value of "y").

Based on this, let's check each relation:

1) {
`(0, 3), (1, 2), (1, 4), (2, 1)`}

This is not a function, because the input value 1 has two different output values (2 and 4)

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

This is not a function, because the input value 3 has two different output values (-1 and 2)

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

This is not a function, because the input value 2 has four different output values (-4, -2, 1 and 3)

4) {
`(-4, -3), (0, -3), (1, -3), (4, -3)`}

This is a function, because each input value has one output value.