=0 ⇒ 2+2‌sin‌x.sin2‌frac‌x‌2=0 ⇒ 2+sin‌x(1−cos‌x)=0 ⇒ 4+2‌sin‌x(1−cos‌x)=0 ⇒ 4+2‌sin‌x−sin‌2‌x=0 ⇒ sin‌2‌x=2‌sin‌x+4 Above is not possible for any value of x as LHS has maximum value 1 and RHS has minimum value 2. Hence, there is no solution.