Evaluate ddx[cos(x2)]\frac{d}{dx}[\cos(x^2)]dxd[cos(x2)].
−2xsin(x2)-2x\sin(x^2)−2xsin(x2)
−sin(x2)-\sin(x^2)−sin(x2)
2xcos(x2)2x\cos(x^2)2xcos(x2)
x2sin(x)x^2\sin(x)x2sin(x)