All right. If the derivative is small, it's not changing, maybe want to take a larger step, but let's not worry about that all right?

好，如果导数很小的话，函数就基本没什么变化,可能我们就想把步子迈大一点儿了,但是别为这个担心？

麻省理工公开课 - 计算机科学及编程导论课程节选

All right, what we gonna do, we want to take a derivative of this thing.

接下来我们要求导了

耶鲁公开课 - 博弈论课程节选

This function will have the right second derivative.

这个函数会得出正确的二阶导数

耶鲁公开课 - 基础物理课程节选

Well, unfortunately, we know this is not the right answer, because if you take the first derivative, I get 2t.

遗憾的是,我们知道这还不是正确答案,因为如果对它求一阶导数,会得到2t

耶鲁公开课 - 基础物理课程节选