Respuesta :

[tex]4\sin^2x-4\sin x+1=(2\sin x-1)^2=0\implies \sin x=\dfrac12[/tex]

This happens for [tex]x=\dfrac\pi6+2n\pi[/tex] and [tex]x=\dfrac{5\pi}6+2n\pi[/tex] where [tex]n[/tex] is any integer.