春雨(李商隐)
∫lnxdx/x=∫lnxdlnx=(1/2)(lnx)^2+c∫sinx(cosx)^3dx=-∫(cosx)^3dcosx=-(1/4)cos^4x+c∫arctgxdx=xarctgx-∫x/(1+x^2)dx=xarctgx-(1/2)∫d(x^2+1)/(x^2+1)=xarctgx-(1/2)ln(x^2+1)+c
