a function has exactly 1 x for every y
no x repeats with a differnt y
but y's can repeat
example:
an example of a function is like the points (1,2), (-1,2) (3,4)
you see, the y=2 repeats, but with a differtn x so that is still a function
a not function is like the points (1,2), (1,3), (3,4)
you see, the x=1 repeats with 2 and 3
look at the examples
the first option
not a function because -3 repeats with 5 and 4
2nd, this is a function because no x repeats with a different y
3rd, not a function because x=0 repeats with -1 and 0
4th, not a function because -12 repeats with 4 and 24
answer is 2nd point (the one with {(-8,-2), (-4,1), (0,-2), (2,3), (4,-4)} )
