1)3sin^2x-4sinxcosx+2cos^2x=0
2)sin^2x-9sinxcosx+3cos^2x=-1

1)3sin²x-4sinxcosx+2cos²x=0/cos²x≠03tg²x-4tgx+2=0tgx=a3a²-4+2=0D=16-24=-8<0нет решения2)sin²x-9sinxcosx+3cos²x+sin²x+cos²x=0/cos²x≠02tg²x-9tgx+4=0tgx=a2a²-9a+4=0D=81-32=49a1=(9-7)/4=1/2⇒tgx=1/2⇒x=arctg1/2+πna2=(9+7)/4=4⇒tgx=4⇒x=arctg4+πn