I take the time derivative.

我会计算时间导数。

youdao

So, the velocity vector is the derivative of a position vector with respect to time.

速度向量，是位置向量关于时间的导数。

youdao

And so we're going to take the derivative versus time of this equation.

我们要求这个，方程的时间导数。

youdao

If you took the derivative of this, you will get the velocity at time t, it would be: v=v0+at.

如果你对它求导,你就可以知道 t 时刻的速度,即,v=v0+at

耶鲁公开课 - 基础物理课程节选

And the mathematics of that equation involved a double derivative in time of x 0 plus some constant times x equals zero with some constraints on it.

那个数学方程式,包括了x对时间的二阶导数,加上常数乘以x等于,还有一些限制条件。

麻省理工公开课 - 固态化学导论课程节选

If you want to know how fast it's moving at a given time, if you want to know the velocity, I just take the derivative of this answer, which is 10-10t.

如果你想知道它在给定时刻的运动有多快,如果你想知道它的速度,我只要对这个式子求导,得到10-10t

耶鲁公开课 - 基础物理课程节选

From the looks of it ECRI takes the first principle component of these four variables and then charts the first time derivative.

FORBES: On Lakshum Achuthan and ECRI: This is Becoming Embarrassing for Everyone