I'm gonna use sine of theta, oh sorry, sine of phi.

我要使用弦 theta， 哦，弦 phi。

When you come up with something that's 4 pi arccotangent square root of phi, and you've derived it, you do feel like you created something.

当你想出“4arccot 下” 并推导出来时，你会觉得自己创造一些东西。