定积分计算中一个结论的推广

Quote a conclusion drawn from definite integration to other integration

在定积分计算中,常常可以利用一个结论来简化计算偶函数、奇函数在对称于原点的区间上的定积分,这个结论能否在重积分计算中使用?本文给出该结论的推广使用方法。

A conclusion can often be used to simplify the calculating process of definite integration if an odd or even function is just situated on the interval which is symmetry about origin. Whether can the conclusion be used in the iterated integral? The answer is ' yes'.