Question

求解arctan e^x/e^(2x)的不定积分

Answer 1

简单计算一下即可，答案如图所示

Answer 2

∫arctan (e^x)/(e^x) dx
=-∫(arctan (e^x) de^(-x)
=-arctan(e^x) / e^x + ∫ dx/(1+e^(2x) )
let
e^x= tany
e^x dx = (secy)^2 dy
∫ dx/(1+e^(2x) )
= ∫ [1/(secy)^2] .[(secy)^2/tany] dy
= ∫ (cosy/siny) dy
= ln|siny|+C'
= ln| e^x/√(1+e^2x) | + C'
∫(arctan e^x)/(e^x) dx
=- arctan(e^x) / e^x + ∫ dx/(1+e^(2x) )
=- arctan(e^x) / e^x + ln| e^x/√(1+e^2x) | + C
希望对你有所帮助