Question

Which relation is a function?

A.
(6, 5), (1, 1), (6, 4)

B.
(0, 1), (2, 3), (2, 5)

C.
(8, –2), (–2, 5), (6, 0)

D.
(–2, 3), (–5, 9), (–5, 3)

Answer 1

as far as i understand, the first parameter (first digit in parenthesis) is input data and second one is output data
function must give the same output for the same input. It means, that if you give it 1 and it returns 4, it never can return anything else, no matter how much you try

A.
(6, 5), (1, 1), (6, 4) - twice input 6, and got different answers
B.
(0, 1), (2, 3), (2, 5) - twice input 2, and got different answers
D.
(–2, 3), (–5, 9), (–5, 3) - twice input -5, and got different answers

C.
(8, –2), (–2, 5), (6, 0) - no twice input

Answer 2

Solutions

A function is a relation between a set of inputs and a set of permissible outputs. "f(x) = ... " is a way of writing a function. Everything that goes into the function is put inside parentheses the (....).

The correct answer for the relation is a function is (C)

(C) = (8, –2), (–2, 5), (6, 0)