Question

how do you know if something is not a funtion?

Answer 1

Is there a specific question or do you just want to know the definition?

Answer 2

Which of the following does not represent a function?

x −2 0 1 −2 9
y 0 −1 −2 −3 −4


x 3 6 9 12 18
y 2 4 6 8 10


x −3 −1 0 2 4
y −6 −4 −3 −2 −1


x 8 7 4 3 1
y −7 −5 −3 −2 −1

Answer 3

Okay the first way to find out f it is not a function is if there are two y values for one x value

Answer 4

theres none like that?

Answer 5

Yes there is, let's take a look at the first one. We have the points (-2,0), (0,-1), (1,-2), (-2,-3), (9,-4). There are two -2 x values with different y values, therefore not a function.

The other way is to graph them and see it visually.

Answer 6

ohh thanks