уравнение 6 sin^2 x+sinxcosx=cos^2 x
6sin^2x-cos^2x+sinxcosx=0
6tg^2x+tgx-1=0
tgx=t
6t^2+t-1=0
t=(-1+-5)/12
t1=-1/2
t2=1/3
x=arctg1/3+Пk
x=arctg(-1/2)+Пk