二重积

And I is the double integral of over D ,written ,or

这样就称f在D上可积，I称为f在D上的二重积分，记作或

The paper introduces the method of calculating double integral with symmetry,and then puts forward a calculating method by rebuilding integrand and domain of integration reasonably.

本文还介绍了如何利用对称性来计算二重积分，并提出了通过适当改造被积函数和积分区域以利用对称性来简化计算的方法。

Inspired by Chans double series representation formula of_∞~(10), the author constructs a new difference equation on quintuple products, which leads to clarification on the four symmetric differences that are equivalent in pairs.

受Chan得到的_∞~(10)的二重级数表示公式的启发，作者构造一个新的关于五重积的差分公式，并澄清迄今为止所出现的四个对称差恒等式之间成对等价的关系。

The labia have now been sutured together almost completely.The drains and the Foley catheter come out at the top.

此刻阴唇已经几乎完全的缝在一起了，排除多余淤血体液的管子和Foley导管从顶端冒出来。

To get the business done, I suggest we split the difference in price.

为了做成这笔生意，我建议我们在价格上大家各让一半。