Решите,пожалуйста   3cos2x+10sin*2x-6=0

3cos2x+10sin*2x-6=0 3(cos^2x-sin^2x)+20sinxcosx-6(sin^2x+cos^2x)=0 3cos^2x-3sin^2x+20sinxcosx-6sin^2x-6cos^2x=0 9sin^2x-20sinxcosx+3cos^2x=0   /:cos^2x≠0 9tg^2x-20tgx+3=0 tgx=t D=400-108=292 t=(20+2√73)/18=(10+√73)/9 t=(20-2√73)/18=(10-√73)/9   tgx=(10+√73)/9 x=arctg(10+√73)/9+pik, k∈Z   tgx=(10-√73)/9 x=arctg(10-√73)/9+pik, k∈Z