Question

1. Which of the following relations is not a function?
(7, 4), (-5, 2), (4, 1), (-7, 2)

(4, 4), (-5, 2), (4, 1), (-7, 2)

(-5, 4), (4, 2), (7, 1), (-7, 5)

(-7, 4), (4, 3), (-5, 1), (7, 2)

Answer 1

in order pair first value is x and 2nd one is y
like this (x,y )
so if there is x's values repeated then relation is not a function
for example (3 , 2)(3 ,4)(4,6)
this relation is not a function bec there are same x values 3 repeated

Answer 2

every x number should pair with exactly one y number