Sin(3x) - 2sin(x) = 0 sin(3x) = 3sin(x) - 4sin^3(x)
3sin(x) - 4sin^3(x) - 2sin(x) = 0
-4sin^3(x) + sin(x) = 0 |: (-1)
4sin^3(x) - sin(x) = 0
sin(x)*(4sin^2(x) - 1) = 0
sin(x) = 0 и 4sin^2(x) = 1
Первый x
sin(x) = 0
x = pi*n (n принадлежит Z)
4sin^2(x) = 1 |: 4
sin^2(x) = 1/4
sin(x) = +- 1/2
Второй x
sin(x) = 1/2
x = (-1)^n * pi/6 + pi*n (n принадлежит Z)
Третий х
sin(x) = -1/2
x = (-1)^(n+1) * pi/6 + pi*n (n принадлежит Z)