Question

这2个视频的背景音乐叫什么名字

www.56.com/u26/v_NDI0ODAyOTM.html
v.ku6.com/show/ULJflC89892tIuxT.html

Answer 1

凑微分做法：∫(1-x^6)/(6x^6(1+x^6))d(x^6)为了方便写可以设t=x^6=(1/6)*∫(1-t)/t(1+t)有理函数的积分,待定系数法A/t-B/(1+t)=(1-t)/t(1+t)所以A(1+t)-Bt=1-tA=1,A-B=-1=>B=2(1/6)*∫(1-t)/t(1+t)=(1/6)∫[1/t-2/(1+t)]dt=(1/6)lnt-(1/3)ln(1+t)+C=(1/6)lnx^6-(1/3)ln(1+x^6)+C=lnx-(1/3)ln(1+x^6)+C