A nice point made by Anonymous and PhilWilson. It is true that relations of the heart are not the same as relations of numbers. People not believing this no mathematical equation can predict what gift gift your valentine will want on this Valentine's Day:) Having said that I think there is no end to the argument whether emotions like love are matters of the heart or produced mathematically controlled events in the brain. And now on a lighter note, for all those who believe that mathematics can describe everything including love, two proofs:

Firstly, some gems of quotes from this page: mathematical love quotes for valentines day:

* I'm a fraction of what I should be without you... you complete me.

* You and I are living proof one plus one equals three, happy valentines day to a dad to be

Now this is one great use of applied mathematics, right? Caution: Use the above quotes only if your valentine is a geek :)

Second proof: these beautiful love equations from http://www.walkingrandomly.com/?p=2326

Also do read this interesting article on valentine programming apparently people are researching how mathematics can explain lost love and what not. Applied mathematics is a whole ocean out there.