1-8sin*cosx+6cos^2x=0

1 - 8sinxcosx + 6 cos²x = 0 sin²x - 8sinxcosx + 7 cos²x = 0 Делим на cos²x tg²x - 8tgx + 7 = 0 tgx = 1; tgx = 7 x = П/4 + Пn; n є Z x = arctg7 + Пn ; n є Z