Question

Identify the relation that is also a function.
A) (3,4),(2,3)(3,6),(2,0)
B) (2,-1),(3,0),(4,6),(1,-3)
C) (5,0),(5,1),(5,2),(0,4)
D) (4,2),(4,-2),(9,3),(-3,9)

Answer 1

Hint: It won't be a function if there are two pairs with the same left coordinate but different right coordinates.

Take choice (A) for example. It's not a function because you have (3,4) and (3,6). Same left coordinate (3) but different right coordinates (4 and 6)

Answer 2

so its D

Answer 3

Do you see any pairs in D with the same left coordinate but different right coordinates?
Remember, if such pairs exist [such as (3,4) and (3,6) in A] then the relation will NOT be a function, but you're looking for the one that IS a function.

Answer 4

ooo its B :)

Answer 5

Yes, it's B.

Answer 6

thanks :)