也就是二重和三重积分的内容，以及平面和空间中的向量积分。

And so that was stuff about double and triple integrals and vector calculus in the plane and in space.

youdao

其中一种说明了，在向量场上，沿逆时针方向，向量做的功等于，平面区域上旋度F的二重积分。

So, one of them says the line integral for the work done by a vector field along a closed curve counterclockwise is equal to the double integral of a curl of a field over the enclosed region.

youdao