作者copps (>"<)
看板trans_math
标题[积分] 旋转体体积
时间Mon Apr 12 12:18:47 2010
考古题:
A solid has its base the region in the xy-plane bounded by the graph of
y^2=4x and y=4x .If every cross section by a plane perpendicular to the
x-axis is a semicircle ,find the volume of the solid [成大财经]
x=4
sol: V = 1/2 S πy^2 dx (x=0到4 2分之1 πy平方的积分)
x=0
PS.以上是书本的解答,不知道是我英文太滥还是哪边有问题..
不知道为什麽要乘以 1/2 ,麻烦高手解题
※ 编辑: copps 来自: 163.26.167.187 (04/12 12:43)
1F：→ copps:有人知道吗..还是解答错了?114.137.132.154 04/13 13:23