Find ddx[1+cos(2x)]\frac{d}{dx}[\sqrt{1 + \cos(2x)}]dxd[1+cos(2x)].
−2sin(x)-\sqrt{2} \sin(x)−2sin(x)
2cos(x)\sqrt{2} \cos(x)2cos(x)
−sin(2x)-\sin(2x)−sin(2x)
−2sin(x)-2 \sin(x)−2sin(x)