Gerald Lambeau: Mod f-x-square, d-x. So please finish Percival for next time. I know many of you had this as undergraduates, but it won't hurt to brush up. Thank you, Steven. I also put an advanced Fourier system on the main hallway chalkboard. I'm hoping that one of you might prove it by the end of the semester. Now the person to do so will not only bein my good graces but also go on to fame and fortune by having their accomplishment recorded and their name printed in the auspicious MIT Tech. Former winners include Nobel laureates, Field's Medal winners, renowned astrophysicists and lowly MIT professors. Well, that's all. If you have any questions, I'm sure that Tom has the answers.
妙語佳句，活學活用
1. Mod f-x-square, d-x
Mod 是數學中的取余函數，就是取兩個數的余數，比如：
mod(10,3) 結果為1
mod(10,-3) 結果為-2
mod(-10,-3) 結果為-1
mod(-10,3) 結果為2
mod ︳f(x)︳2 結果為dx。
2. brush up
這里的意思是“review, refresh one's memory 復習”的意思，也寫作brush up on，比如：Nell brushed up on her Spanish before going to Honduras.內爾在去洪都拉斯前復習了一下她的西班牙語。
3. Fourier system
傅立葉（Fourier, Jean Baptiste Joseph, 1768-1830），是傅立葉級數（三角級數）創始人。他是
這個片語的意思是“in someone's favor or good opinion 受到某人的寵愛”，也可以表示為 in someone's good books / in the good graces of，比如：Ruth is back in her mother's good graces. 魯斯重新得到了媽媽的寵愛。
