You can put this solution on YOUR website!
When working with domains and ranges and a question asks you to use a mapping diagram to represent the relation, how do you do that?
I can't really show you on the computer, but I should be able to get you to visualize it.
Draw an tall oval and put all your x's or independent variables in it.
Then draw another tall oval and put all your y's or dependet values in it.
Draw arrows from the x's in the first oval to their corresponding y-values in the second oval,
That's a mapping diagram, functions will only have one arrow going out of every x value.