∫（t-sint）^2sintdt
=∫(t^2sint+sint^2sint-2tsint^2)dt
=∫t^2sintdt+∫(1-cost^2)sintdt-2∫tsint^2dt
=-∫t^2dcost-∫(1-cost^2)dcost-∫t*(1-cos2t)dt
=-t^2cost+∫2costdt-cost+cost^3/3-t^2/2+∫tdsin2t
=-t^2cost+2sint-cost+cost^3/3-t^2/2+tsin2t-∫sin2tdt
=-t^2cost+2sint-cost+cost^3/3-t^2/2+tsin2t-1/2*sin2t^2