3+sin 2x=4sin^2x

3+sin2x=4sin^2xsin2x=2sinx*cosx3+2sinx*cosx=4sin^2x Делим на sin^2x3/sin^2x+2ctgx=41/sin^2x=1+ctg^2x3 (1+ctg^2x)+2ctgx=43ctg^2x+2ctgx-1=0D=4+12=16ctgx=1/3 -> x=arcctg 1/3+pi*kctgx=-1 ->x=3pi/4+pi*l