If 2sin2⁡(π/2)cos2⁡x=1−cos⁡(πsin⁡2x),x≠(2n+1)π/2 ,n∈I then cos 2x is equal to

The given equation is equivalent to  2sin2⁡(π/2)cos2⁡x=2sin2⁡((π/2)sin⁡2x) or  cos2⁡x=sin⁡2x or  cos⁡x(cos⁡x−2sin⁡x)=0⇒ 1−2tan⁡x=0 as cos⁡x≠0,x≠(2n+1)π2 or  tan⁡x=12⇒ cos⁡2x=1−tan2⁡x1+tan2⁡x=35