Warning: this post is not for the math novice. But if you are trying to get the attention of another math geek or nerd or whatever they are called, you might try some of these:
(The first couple of them came from a conversation on the bus to the state math contest between teenage boys that are taking calculus this year...)
"If I was sine squared and you were cosine squared, together we would be one."
"I don't know if you're in my range, but I'd sure like to take you back to my domain."
"I wish I was your derivative so I could lie tangent to your curves."
"If I were a function you would be my asymptote - I always tend towards you."
"I don’t like my current girlfriend. Mind if I do a you-substitution?"
"I'm not being obtuse, but you're acute girl."
(After the convo on the bus, I came home and googled the topic. Here are some of my favorites that I found at http://www.pickuplinesgalore.com/math.html Beware--some of the ones on the site are a little bit...well, you know. :)
4 weeks ago