Answer:
The correct options are 1, 2 and 4.
Step-by-step explanation:
A relation is a function if and only if there exist a unique output for each input.
In option 1, the given orderder pairs are
(2,-5), (4,-5), (6,2), (8,3)
For all x-values we have unique y-values. Set 1 is a function.
In option 2, the given orderder pairs are
(-1,5), (3,5), (6,5), (9,5)
Set 2 is a function.
In option 3, the given orderder pairs are
(3,-4), (5,2), (3,8), (6,7)
Here, for x=3 we have two y-values -4 and 8. Set 3 is not a function.
In option 4, the given orderder pairs are
(0,3), (4,2), (-1,7), (0,3)
For all x-values we have unique y-values. Set 4 is a function.
In option 5, the given orderder pairs are
(-1,1), (-1,6), (-1,8), (-1,0)
For x=-1 we have more than one y-values. Set 5 is not a function.
In option 6, the given orderder pairs are
(-4,2), (3,-2), (-4,-2), (5,1)
For x=-4 we have more than one y-values. Set 6 is not a function.
Therefore the correct options are 1, 2 and 4.
