Question

Which relation below is not a function?
A. {(1,2), (2,3), (5,7)}
B. {(2,2), (2,3), (1,7)}
C. {(1,3), (2,3), (7,5)}
D. {(-1,2), (2,-3), (-5,-7)}

Answer 1

I'm going with B.

Answer 2

Correct. Since in B the x-coordinate 2 is matched to two different y-coordinates, 2 and 3, B is not a function.