Question

Which relations are functions?

Select Function or Not a function for each graph.

Answer 1

Answer: 1 and 2 are functions. 3 and 4 are NOT functions.

Step-by-step explanation: because

Answer 2

A function is a relation that associates each element x of a set X, to a single element y of another set Y.

Graph #4 is not a function. For x = 4 we have y = -2 and y = 2.