1. 2sin x + cos x = 0
Преобразуем уравнение 2sin x = - cos x <span> tg x = - 1/2, x = - arctg 1/2 + π n , n принадлежит Z.</span> 2. <span>3cos^2x/cos^x-5sin^2x/cos^2x+2sinxcosx/cos^2x=0 3-5tg^2x-2tgx=0 5tg^2x+2tgx-3=0 Tgx=t D=64=8 T1=3/5 T2=-1 Tgx=-1 X=-п/4+пn Tgx=3/5 X=arctg3/5+пn</span>