1+sinx·cosx-3cos²x=0 6cos²x-2sin2x=1 tg²x-3tgx+4=3ctgx-ctg²x sinx·cosx-cos²x=1

1+sinx·cosx-3cos²x=0
sin^2x+cos^2x+sinxcosx-3cos^2x=0/cos^2x
tg^x+1+tgx-3=0
a^2+a-2=0
D=3
a1=-2
a2=-1 x=-pi/4+pin 3) sinxcosx-cos^2x=1 tgx-1=1 tgx=2 x=arctg2+pin