the XKCD costume idea is genius!
I've seen lots of Halloween comics on spikedmath. It's making me bored.
hahaha worst pick up line ever!
tits building and sine wave?
Sine wave: if you have a graphing calculator plug in f(x)=sin(x) or y=sin(x) and you will get a sine wave. Or go here: https://www.google.com/search?q=sine+wave&safe=active&es_sm=122&source=lnms&tbm=isch&sa=X&ved=0CAcQ_AUoAWoVChMIiNS68N-myAIVgUc-Ch1x2wnK&biw=1920&bih=989
If you're an adult with two small children, you could go as a tangent, while they are sine and cosine...
I guess if you only had one kid, the guy could dress up as sin and the girl as cos to get a tan.
of course you never know who was on top so I guess its just as probable the kid was a cot.
I think there may be a costume in Brown Sharpie's Coswine and negative Coswine Ideas (found here: http://brownsharpie.courtneygibbons.org/?p=65 and http://brownsharpie.courtneygibbons.org/?p=98 )
I have the right avatar for that coswine idea--but this is also a Yellow Pig!
Natural log...! This is as good as the "tangent to your curve" one. Now it is formally a new entry of my library of math jokes.
On mathfail are some xkcd costumes: http://mathfail.com/2010/10/xkcd-halloween-costume.html