作者Qmmm (割掉Q)
看板trans_math
标题[积分]
时间Mon Mar 23 23:04:06 2009
Evaluate the line integral
xdy - ydx
I = ∫---------------------
c (x+2y)^2 + (3x-y)^2
where C is the closed curve defined by (x+2y)^2 + (3x-y)^2 = 1 in
counterclockwise direction.
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※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 140.112.128.93
1F：→ fong1014:是2PI/7吗~ 61.217.160.208 03/24 12:51
2F：→ mathmanliu:是 2π/7 没错! 123.193.32.236 03/24 21:11
3F：推 fong1014:那就设x+2y=u 3x-y=v；xdy - ydx 用u,v 61.217.152.63 03/24 21:41
4F：→ fong1014:取代，积分路径变成一通过原点的封闭线。 61.217.152.63 03/24 21:42
5F：→ Qmmm:嗯 我会了 谢谢两位高手^^ 140.112.128.93 03/24 21:58