Which of the following relations is not a function?

(8, 4), (-5, 2), (4, 1), (-6, 2)

(-5, 4), (4, 2), (8, 1), (-6, 5)

(-6, 4), (4, 3), (-5, 1), (8, 2)

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

my answer is b

1 answer

nope. d

a relation is not a function if for some x=h, there is more than one pair with that x-value.

according to d,
f(4) = 4
f(4) = 1

both cannot be true for a function.

All the other relations have distinct x values for all the pairs. They are functions.