And this is finally where I have left the world of surface integrals to go back to a usual double integral.

也就是最终要摆脱曲面积分，回到常规的二重积分。

youdao

And this is finally where I have left the world of surface integrals to go back to a usual double integral.

也就是最终要摆脱曲面积分，回到常规的二重积分。

youdao