4 sin ^2x-4 sin x+1 =0

[tex]4 sin ^2x-4 sin x+1 =0 \\(2sinx-1)^2=0 \\2sinx-1=0 \\2sinx=1 \\sinx= \frac{1}{2} \\x_1= \frac{\pi}{6} +2\pi n,\ n \in Z \\x_2=\frac{5\pi}{6} +2\pi n,\ n \in Z[/tex]