Evaluate ddx[x2cosx]\frac{d}{dx}[x^2 \cos x]dxd[x2cosx].
2xcosx−x2sinx2x\cos x - x^2\sin x2xcosx−x2sinx
2xcosx+x2sinx2x\cos x + x^2\sin x2xcosx+x2sinx
−x2sinx-x^2\sin x−x2sinx
−2xsinx-2x\sin x−2xsinx