∫xcosx/2dx
=∫x(1+cosx)/2 dx
=∫x/2 dx+∫(xcosx)/2 dx
=x²/4+1/2∫xdsinx
=x²/4+1/2*xsinx+1/2∫sinxdx
=x²/4+1/2*xsinx-1/2*cosx+C
所以原式=(x²/4+1/2*xsinx-1/2*cosx)-(0+0-1/2*1)
=x²/4+1/2*xsinx-1/2*cosx+1/2
∫xcosx/2dx
=∫x(1+cosx)/2 dx
=∫x/2 dx+∫(xcosx)/2 dx
=x²/4+1/2∫xdsinx
=x²/4+1/2*xsinx+1/2∫sinxdx
=x²/4+1/2*xsinx-1/2*cosx+C
所以原式=(x²/4+1/2*xsinx-1/2*cosx)-(0+0-1/2*1)
=x²/4+1/2*xsinx-1/2*cosx+1/2