Уравнение: sin6x=cos4x0 меньше x меньше 90

sin 6x = cos 4x sin 6x - cos 4x = 0 cos (π/2 - 6x) - cos 4x = 0 -2 sin ((π/2 - 6x+ 4x)/2) * sin ((π/2 - 6x - 4x)/2) = 0 -2 sin (π/4 - x) * sin (π/4 - 5x) = 0 sin (π/4 - x) = 0   |  sin(π/4 - 5x) = 0 π/4 - x = πk         |  π/4 - 5x = πk x = π/4 - πk         |  x = π/20 - πk/5 k ∈ Z Ответ: x = π/4 - πk , x = π/20 - πk/5 , k ∈ Z