Question

∫ x^ 2cosxdx

Answer 1

∫x^2cosxdx
=∫x^2d(sinx)
=x^2*sinx-∫sinxd(x^2)
=x^2*sinx-2∫xsinxdx
=x^2*sinx+2∫xd(cosx)
=x^2*sinx+2[xcosx-∫cosxdx]
=x^2*sinx+2xcosx-2sinx+C

Answer 2

∫x^2cosxdx吧，我见过这道题：∫x^2cosxdx=∫x^2d(sinx)=x^2*sinx-∫sinxd(x^2)=x^2*sinx-2∫xsinxdx =x^2*sinx+2∫xd(cosx)=x^2*sinx+2[xcosx-∫cosxdx]=x^2*sinx+2xcos...

Answer 3

∫x²cosxdx
=∫x²d(sinx)
=x²sinx-∫sinxd(x²)
=x²sinx-2∫xsinxdx
=x²sinx+2∫xd(cosx)
=x²sinx+2xcosx-2∫cosxdx
=x²sinx+2xcosx-2sinx +C