作者Qmmm (割掉Q)
看板trans_math
標題[積分]
時間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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◆ From: 140.112.128.93
→ fong1014:是2PI/7嗎~ 61.217.160.208 03/24 12:51
→ mathmanliu:是 2π/7 沒錯! 123.193.32.236 03/24 21:11
推 fong1014:那就設x+2y=u 3x-y=v；xdy - ydx 用u,v 61.217.152.63 03/24 21:41
→ fong1014:取代，積分路徑變成一通過原點的封閉線。 61.217.152.63 03/24 21:42
→ Qmmm:嗯 我會了 謝謝兩位高手^^ 140.112.128.93 03/24 21:58