1 + 2 sin4x+3cos^2(2x)=0
cos^2(2x) + sin^2(2x) + 4sin2xcos2x + 3cos^2(2x) = 0
sin^2(2x)+ 4sin2xcos2x + 4cos^2(2x) = 0 |:cos^2x
tg^2(2x) + 4tg2x + 4 = 0
(tg2x + 2)^2 = 0
tg2x + 2 = 0
tg2x = -2
2x = arctg(-2) + Пk
x = -0,5arctg2 + 0,5Пk
