1 Which relation is not a function?

1) { (1,5), (2,6), (3,6), (4,7) }

2) { (4,7), (2,1), (-3,6), (3,4) }

3) { (-1,6), (1,3), (2,5), (1,7) }

4) { (-1,2), (0,5), (5,0), (2,-1) }

3 because the x value has been repeated

3) { (-1,6), (1,3), (2,5), (1,7) }

Step-by-step explanation:

functions have to pass the vertical line test to be called a function

if they don't pass they are not a function

this means that no x values can repeat

In option 1

none of the x values repeat so that means it is a function

1, 2, 3, 4

in option 2

none of the x values repeat so that means it is a function

4,2,-3,3

in option 3

one of the x values repeats so that means it is not a function

-1,1,2,1 the ones repeat

in option 4

none of the x values repeat so that means it is a function

-1,0,5,2

so that means that option 3 is not a function