Evaluate the Indefinite Integral ∫cot 2x dx?
回答 (1)
Evaluate the Indefinite Integral ∫Cot(2x)dx?
Sol
∫Cot(2x)dx
Set y=Sin(2x)
dy/dx=dSin(2x)/dx=[dSin(2x)/(2x)]*(d2x/dx)
=2Cos(2x)dx
dy=2Cos(2x)dx
(1/2)dy=Cos(2x)dx
∫Cot(2x)dx
=(1/2)∫Cos(2x)/Sin(2x)dx
=(1/2)∫dy/y
=ln|y|/2+c
=ln|Sin(2x)|/2
收錄日期: 2021-04-30 22:47:22
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20181218164936AAbcbct
檢視 Wayback Machine 備份