sin2x-cos2x = tgx2sinx*cosx - (1-2sin²x) = sinx/cosx2sinx*cosx - 1+2sin²x = sinx/cosx |*cosx2sinx*cos²x-cosx + 2sin²x*cosx = sinx2sinx*cos²x-cosx+2sin²x*cosx - sinx =0На множители2sinx*cosx(cosx+sinx) - (cosx+sinx)=0(cosx+sinx)(sin2x-1)=0Произведение равно 0 cos+sinx = 0 |:cosxcosx/cosx + sinx/cosx = 0Как видно sinx/cosx = tgx1+tgx = 0tg x= -1
+ \pi n \\ x=- \frac{ \pi }{4} + \pi n)
и sin 2x = 1

Ответ: -π/4+πn, π/4+πn