Question

Which relation is a function? choose all the correct answers.[1] (1, 0), (3, 0), (1, 1), (3, 1) (1, 3) [2] (1, 1), (2, 2), (3, 3), (4, 4), (5, 8)[3] (2, 7), (6, 5), (4, 4), (3, 3), (2, 1)[4] (9, −3), (9, 3), (4, −2), (4, 2), (0, 0)

Answer 1

A relation is a function if an input value has only one output value. This means that a value of x must have only one value of y. Looking at the options,

1) for x = 1, there are different values of y. They include y = 0, 1, 3

for x = 3, y = 0, 1

This means that it is not a function

2) No value of x has more than one value of y. Thus, no input has more than one output. This means that it is a function

3) for x = 2, there are different values of y. They include y = 7, 1

This means that it is not a function

4) for x = 9, there are different values of y. They include y = - 3, 3

for x = 2, there are different values of y. They include y = - 2, 2

This means that it is not a function

Thus, the correct option is

[2] (1, 1), (2, 2), (3, 3), (4, 4), (5, 8)