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

以前算过-,这是能量守恒，为了算出,简谐振荡的周期，我们求时间导数。

We've done this before-- this is the conservation of energy, and in order to find the period of the simple harmonic oscillation, we take the time derivative.

youdao

我们首先要做的事是,求偏导数，fx是多少？

What we would start doing immediately is taking the partial derivatives. What is f sub x?

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

And, of course, see that either way we do that we'll have an equality.

利用两种不同的顺序求二阶导数,就可以得到一个等式。

麻省理工公开课 - 热力学与动力学课程节选

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