срочно!! cos8x-5sin4x-3=0

1 - 2sin²4x - 5sin4x - 3 = 0-2sin²4x - 5sin4x - 2 = 02sin²4x + 5sin4x + 2 = 0Пусть t = sin4x, t ∈ [-1; 1].2t² + 5t + 2 = 0D = 25 - 2•2•4 = 9 = 3²t1 = (-5 + 3)/4 = -2/4 = -1/2t2 = (-5 - 3)/4 = -8/4 = -2 - постронний кореньОбратная замена: sinx = -1/2x = (-1)ⁿ+¹π/6 + πn, n ∈ Z