作者ian5j6 (Persistent Effort)
看板trans_math
标题[积分] 一题积分
时间Mon May 3 18:36:59 2010
积分[(sin(t))^4 + 4*(sin(t)*cos(t))^2]^(1/2) dt
因为怎麽算都算不出来，希望板上有人会
感激不尽!!!
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※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 140.115.208.217
1F：→ a88241050:把(sin(t))^2提出来 140.135.32.38 05/03 18:41
2F：→ ian5j6:然後?140.115.208.217 05/03 19:08
3F：→ a88241050:然後sin(t)dt就变成d(-cos(t))啊 140.135.32.38 05/03 19:09
4F：→ ian5j6:than???140.115.208.217 05/03 19:10
5F：→ a88241050:..根号里面就变成sin(t)^2+4*cos(t)^2 140.135.32.38 05/03 19:12
6F：→ a88241050:sin(t)^2+4*cos(t)^2=1+3*cos(t)^2 140.135.32.38 05/03 19:12
7F：→ a88241050:再换变数 140.135.32.38 05/03 19:13
8F：→ ian5j6:对我就是做到这里不会的请赐教~140.115.208.217 05/03 19:14
9F：→ a88241050:令3*cos(t)^2=tan(x)^2 140.135.32.38 05/03 19:15
10F：→ ian5j6:最後要做到sec的三次方积分?140.115.208.217 05/03 19:20
11F：→ ian5j6:一题积分磁力线长度的题目要这麽复杂?140.115.208.217 05/03 19:20