求∫π/20x2sinxdx.
∫0π/2sinxdx =-∫0π/2x2dcosx =-x2cosx|0π/2+∫0π/2cosxdx2 =0+∫0π/22xcosxdx =2∫0π/2xdsinx =2xsinx|0π/2-2∫0π/2sinxdx =π-2(-cosx)|0π/2=π-2.
求∫π/20x2sinxdx.
∫0π/2sinxdx =-∫0π/2x2dcosx =-x2cosx|0π/2+∫0π/2cosxdx2 =0+∫0π/22xcosxdx =2∫0π/2xdsinx =2xsinx|0π/2-2∫0π/2sinxdx =π-2(-cosx)|0π/2=π-2.