Question

Which of the following relations is NOTſa function? *

{(1,5), (3, -1), (7.9)}
{(1, 1), (2, 2), (3, 3)}

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

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

Answer 1

{(1,5), (2,5), (4,5)} is not a function