求下列不定积分1.∫sinx⼀(1+sinx)dx 2.∫(xcosx)⼀sin눀xdx

2025-01-02 18:16:21
推荐回答(2个)
回答1:

详细过程见图

回答2:

∫sinxdx/(1+sinx)
=∫dx-∫dx/(1+sinx) 1+sinx=1+cos(π/2-x)=2cos(π/4-x/2)^2
=∫dx-∫d(x/2)/cos(π/4-x/2)^2
=x+tan(π/4-x/2)+C

∫xcosxdx/(sinx)^2
=∫xd(-1/sinx)
=x*(-1/sinx)+∫dx/sinx
=-x/sinx-(1/2)ln|1+cosx|/|1-cosx|+C
=-x/sinx-ln|1+cosx|/|sinx|+C