2sin^2x + 1,5sin2x-3cos2^x=1 очень надоо!!
sin^2x - cos^2x = -1/2 /*2
2sin^2x - 2cos^2x = -1
2sin^2x - 2cos^2x = -sin^2x-cos^2x
2sin^2x - 2cos^2x + sin^2x + cos^2x = 0
3sin^2x - cos^2x = 0 /:cos^2x≠0
3tg^2x - 1 = 0
tg^2x = 1/3
tgx = ± √3/3
x= ± pi/6 + pik, k∈Z