令arcsinx=u,则:x=sinu,∴cosu=√(1-x^2),且dx=cosudu,∴∫xarcsinxdx=∫usinucosudu=(1/2)∫usin2udu=-(1/4)∫ud(cos2u)=-(1/4)ucos2u+(1/4)∫cos2udu=(1/8)sin2u-(1/4)ucos2u+C=(1/4)sinucosu-(1/4)u[1-2(sinu)^2]+C=(1/4)x√(1-x^2)-(1/4)arcsinx+(1/2)x^2+C。
这样