Question

Which of the following graphs is not a function?

Click on the graph until the correct graph appears

Answer 1

graph #1 is NOT a function

Answer 2

Hint: Functions cannot have two values of y that associate with one value of x. Drawing vertical lines help you verify this - if you are able to touch 2 points with the same vertical line, then it isn't a function.

Answer 3

Hint: if you get your pencil and go across the graph, if to points touch the pencil at the same time it is NOT a function. But if only 1 point touches your pencil it is a function.

Hope that helps :)