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

Question

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

Answer 1

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