Cos^2x-7sinxcosx+12sin^2x=0

Ответ:

arctg(1/4); arctg(1/3)

Пошаговое объяснение:

разделим на cos²x

1 - 7tgx + 12tg²x = 0

D = 49 - 48 = 1

tgx1 = (7 - 1)/24 = 1/4

x1 = arctg(1/4)

tgx2 = (7+1)/24 = 1/3

x2 = arctg(1/3)