求不定积分,完整过程谢谢

如题所述

第1个回答  2016-12-20

本回答被网友采纳
第2个回答  2016-12-20
4x=tant
∫dx/√(1+16x²)=1/4∫dtant/√(1+tan²t)
= 1/4∫dt/cost=1/4∫dsint/cos²t
=1/4∫dsint/(1-sin²t)=1/4∫dsint/[(1+sint)(1-sint)]
=1/8∫1/(1+sint)+1/(1-sint)dsint
=1/8ln|1+sint|-1/8ln|1-sint|+C
=1/8ln|(1+sint)/(1-sint)|+C
=1/2ln|tant+sect|+C
= 1/2ln|4x+√(1+16x²)|+C本回答被提问者采纳