作者sagu (挽枫)
看板Math
标题[微积] 旋转体和曲线
时间Sun Jun 5 17:17:49 2011
A curve is defined by
{ 2
{ x = t - 2t;
{ 3 2
{ y = -t + 3t ;
Let R be the region enclosed by the loop of the curve. If R is totated about
the line x = -1, find the volume of the resulting solid.
V = ∫2πr(dr)h = 2π∫(x+1)(dx)
2(y-2)
我想问黄色部分怎麽得出
如果可以的话 可以讲详细点
这边都不太会转
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1F：推 lowpitch :当 x=-1, t=1 y=2 绕x=-1转类似沙漏状...大概吧... 06/05 19:15
2F：→ sagu :还是毫无头绪耶.. 06/06 12:56