Помогите решить

Cos4X - SinX = 0

Cos (a+b) - sin (a-b) = (cosb + sinb) (cosa - sina)

a = 5/2 b = 3/2 - > cos4x - sinx =

(cos3/2x + sin3/2x) (cos5/2x - sin5/2x) = 0 - >

cos3/2x + sin3/2x = 0 - > tg3/2x = - 1 - > 3/2x = - π/4 + πn

-> x = - π/6 + 2πn/3

cos5/2x - sin5/2x = 0 - > tg5/2x = 1 - > 5/2x = π/4 + πn - >

x = π/10 + 2πn/5