So, the area elements are actually related by the absolute -10 value of this guy. OK, so if you find -10 as your 10*dxdy answer, then du dv is still ten times dx dy.

所以说，面积其实是跟这个东西的绝对值有关的,如果你们得到的答案是,那么dudv依旧是。

youdao

But, the final answer must be written 100% alone, with understanding of every dot that goes in there. This is an absolute must.

最后的答案必须是100%由自己独自完成，在自己的理解下完成，这是绝对必需的。

youdao

But, the final answer must be written 100% alone, with understanding of every dot that goes in there. This is an absolute must.

最后的答案必须是100%由自己独自完成，在自己的理解下完成，这是绝对必需的。

youdao