这个三重积分怎么破?
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/07/13 06:33:21
这个三重积分怎么破?
![](http://img.wesiedu.com/upload/a/5a/a5a670851e8bbcd96eae9985d514eee3.jpg)
![](http://img.wesiedu.com/upload/a/5a/a5a670851e8bbcd96eae9985d514eee3.jpg)
![这个三重积分怎么破?](/uploads/image/z/16509476-20-6.jpg?t=%E8%BF%99%E4%B8%AA%E4%B8%89%E9%87%8D%E7%A7%AF%E5%88%86%E6%80%8E%E4%B9%88%E7%A0%B4%3F%26nbsp%3B)
原式=∫dθ∫sinφdφ∫(rsinφcosθ)(rsinφsinθ)(rcosφ)r^2dr
(作球面坐标变换)
=∫sinθcosθdθ∫cosφ(sinφ)^3dφ∫r^5dr
=(1/2)∫sin(2θ)dθ∫(sinφ)^3d(sinφ)∫r^5dr
=(1/2)[(1-(-1))/2][(1-0)/4][(1-0)/6]
=1/48.
(作球面坐标变换)
=∫sinθcosθdθ∫cosφ(sinφ)^3dφ∫r^5dr
=(1/2)∫sin(2θ)dθ∫(sinφ)^3d(sinφ)∫r^5dr
=(1/2)[(1-(-1))/2][(1-0)/4][(1-0)/6]
=1/48.