Who says you need to be serious on a Valentine Day! You can send funny cards and stuffs to your valentine on the special day. I found this little mathematical equation for you graphing calculator.

r = a(1 - cos(theta))

Plot that on your TI-89.

That was bryan’s idea. He has a nice and funny Valentine card in the page too:

Got this nice drawing in email : Always be prepared for the worst scenario when you give your heart away (I wish the art were not gender specific though).