作者powerdown (powerdown)
看板Math
标题[微积] dy/dx=cos(x+y),y(0)=π/4
时间Wed Jul 6 17:04:14 2011
dy/dx=cos(x+y),y(0)=π/4
先是另u=x+y,整理可得du/(1+cosu)=dx
再来要如何积分呢??请高手解惑谢谢!!
ANS:-cot(x+y)+csc(x+y)=x+√2 -1
用tan(x/2)去代换答案好像不一样@@
--
※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 59.115.72.223
1F：推 zard1989 :左边上下同乘1-cosu 07/06 18:34