Choose if the following relations are functions or not functions.
{(4, -8), (2,-8), (-8,-8), (0,-8)} is a function or not a function
{(3,9), (-3,1), (5,3), (3,3), (10,14)} is a function or not a function
{(7,2), (8,-1.4) (4.5, -10), (7,2) (1.2,1.8)} is a function or not a function
{(0,0), (1,1), (2,2), (3,3), (4,4)} is a function or not a function
1) This is a function because each x-value in the set is associated with only one y-value.
2) This is not a function because the x-value 3 is associated with two different y-values (9 and 3).
3) This is not a function because the x-value 7 is associated with two different y-values (2 and 2).
4) This is a function because each x-value in the set is associated with exactly one y-value.