3cos²2x - 5sin²x - sin2x = 0
5sin²x + sin2x - 3cos²x = 0
5sin²x + 2sinxcosx - 3cos²x = 0 |:cos²x
5tg²x + 2tgx - 3 = 0
5tg²x + 5tgx - 3tgx - 3 = 0
5tgx(tgx + 1) - 3(tgx + 1) = 0
(5tgx - 3)(tgx + 1) = 0
1) 5tgx - 3 = 0
5tgx = 3
tgx = 3/5
x = arctg(3/5) + πn, n ∈ Z
2) tgx + 1 = 0
tgx = -1
x = -π/4 + πk, k ∈ Z
Ответ: x = arctg(3/5) + πn, n ∈ Z; -π/4 + πk, k ∈ Z.
Если не видно что - то , то спрашивай
(81x^4y^2)(16X^4y^12)=1296x^8 y^14
1. 36у^2-12у+1
2. (-5х)^2-(у)^2=25х^2-у^2