Which relations are functions?
Select Function or Not a function for each graph.




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.
Answer: 1 and 2 are functions. 3 and 4 are NOT functions.
Step-by-step explanation: because