Question

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)}

Answer 1

3) {(−1,6),(1,3),(2,5),(1,7)}

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

Answer 2

3 because the x value has been repeated