Problem
Use a mapping diagram to determine whether the relation is a function
(4,3),(1,5),(1,9),(8,7),(2,12),(4,2)
Solution
For this problem we just need to see if for each value of x we have only and just only one value of y.
And if we check we see that we have two points
(1,5),(1,9)
We can see that the same value x=1 have two corresponding values of y=5 and y=9. So for this case we can conclude that this relationship is not a function
