Question

Which of the following relations is NOT a function?
A. {(1, 1), (2, 4), (3, 6), (4, 8)}
B. {(−5, 25), (5, 25), (−6, 36), (6, 36)}
C. {(4, −4), (3, −3), (3, 3), (4, 4)}
D. {(3, 12), (5, 20), (7, 28), (8, 32)}

Answer 1

C, it has repetitions in the domain (x) values of 4.

Answer 2

yes i agree with @xGuardians

in a function, you cannot have the same input more than once :)

Answer 3

oh and also repetitions of the x value 3 so it's a double whammy! haha