总而言之，我们所做的就是求二阶导数。

And all we did, further, is take that second derivative.

youdao

这是一个临界点，考察它的二阶导数,会发现这确实是一个极大值点。

That is a critical point. And we used the second derivative to see that this critical point is a local maximum.

youdao

那么二阶导数判定是怎样的呢？

So, what does the second derivative test say?

youdao

So I'm hoping you guys are comfortable with the notion of taking one or two or any number of derivatives.

我希望你们,能习惯求一阶,二阶,或者任意阶导数的概念

耶鲁公开课 - 基础物理课程节选

Normally, I will give you a function and tell you to take any number of derivatives.

通常情况下,我会给你一个函数,然后让你求任意阶的导数

耶鲁公开课 - 基础物理课程节选

So if we differentiate this object, I'm gonna find a first order condition in a second.

想要求它的导数,先让我想想一阶条件

耶鲁公开课 - 博弈论课程节选