∫x（sinx+cosx）dx=∫xsinxdx+∫xcosxdx=-∫xd(cosx)+∫xcosxdx=-xcosx+∫cosxdx+∫xd(sinx)=-xcosx+sinx+xsinx-∫sinxdx=-xcosx+sinx+xsinx+cosx∫(π/2~0) x（sinx+cosx）=(-xcosx+sinx+xsinx+cosx)|(π/2~0)=(1+...