更新1:
Actually I solved it quickly after I raised this question. Can I ask, why you can use only a few steps? I need to let u=cotx^2, but you don't need to! u=cotx^2 du=-2x(cscx^2)^2 dx
Integration
回答 (1)
2009-05-17 9:50 pm
✔ 最佳答案
As follows:圖片參考：http://i707.photobucket.com/albums/ww74/stevieg90/01-23.gif
2009-05-17 14:12:52 補充：
其實原理同你設u的一樣,只不過做得呢d多就好似唔使設u呢d野...
2009-05-17 14:15:16 補充：
用你個方法做多次:
Let u=cotx^2
du=-2x(cscx^2)^2 dx
int x(cscx^2)^2 dx
=int x(cscx^2)^2 du/[-2x(cscx^2)^2]
=(-1/2) int du
=(-1/2)u+c
=(-1/2)cotx^2+c
收錄日期: 2021-04-22 00:39:25
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090517000051KK00822