Which of the following sets of ordered pairs represents a function?

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

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

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

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

Answer with Step-by-step explanation:

set of ordered pair is a function if no input value has two output values

i. e. if ordered pair is of form (x, y) then no value of x will have more than one values of y

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

-2 has two output values

so, it is not a function

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

It is a function

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

-1 has m ore than one output values

so, it is not a function

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

2 has two output values

so, it is not a function

Shouldn't the answer be: (-1,4), (1,4), (2,4), (-2,4)