Karina J. Wilkie, Students' use of variables and multiple representations in generalizing functional relationships prior to secondary school, Educational Studies in Mathematics, Vol. 93, No. 3 ...

But if you want to know if a relationship is functional or totally, utterly dysfunctional, here are the 10 big differences that clearly delineate the two. See where your relationship lies.

Do you and your partner simply go through the motions together? Here's how to tell if you're in a loveless relationship.