http://imageshack.com/i/g9dcnrj
why it is wrong????
math…………5pts
2013-11-02 9:19 pm
回答 (2)
2013-11-02 11:20 pm
✔ 最佳答案
第3行轉第4行積分錯誤∫Sec^2 xdx
Set y=Tanx
dy=Sec^2 xdx
∫Sec^2 xdx
=∫dy
=y+c
=Tanx+c
2013-11-02 9:55 pm
第3個 = 號個度有問題吧，
唔係好識打INTEGRATE個符號，我用S代替。
你用INTEGRATION BY PART個時MISS 左1個TERM?
Sudv = uv - Svdu <--- You missed Svdu?
2013-11-02 14:17:41 補充：
你做做下應該係 = -sec x csc x + S csc^2 x dx
之後再用integration by part 拆 S csc^2 x dx ，
會得到 sec x csc x (+postive) + S sec^2 x dx，
剛好消了之前的-sec x csx 同還原。
唔係好識打INTEGRATE個符號，我用S代替。
你用INTEGRATION BY PART個時MISS 左1個TERM?
Sudv = uv - Svdu <--- You missed Svdu?
2013-11-02 14:17:41 補充：
你做做下應該係 = -sec x csc x + S csc^2 x dx
之後再用integration by part 拆 S csc^2 x dx ，
會得到 sec x csc x (+postive) + S sec^2 x dx，
剛好消了之前的-sec x csx 同還原。
參考: me
收錄日期: 2021-04-20 14:29:47
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20131102000051KK00090