但是你知道，它给了你一个例证，其中你可以，把复杂的线积分化成简单些的二重积分。

But, you know, it gives you an example where you can turn are really hard line integral into an easier double integral.

youdao

那么我就能名正言顺地,用R上的某个函数的二重积分来替代通量的线积分。

Then I can actually -- --replace the line integral for flux by a double integral over R of some function.

youdao

除了这些，旋度还有一个用处，如果你还记得，我们讨论平面的时候,当把线积分转换成二重积分的时候。

But another place where this comes up, if you remember what we did in the plane, curl also came up when we tried to convert line integrals into double integrals.

youdao