tg6xcos2x-sin2x-2sin4x=0
sin6xcos2x/cos6x-sin2x-2sin4x=0
sin6xcos2x-sin2xcos6x-2sin4xcos6x=0
sin4x-2sin4xcos6x=0
sin4x(1-2cos6x)=0
x=Пk/4
1-2cos6x=0
cos6x=1/2
x=+-П/18+Пk/3