Question

sin 3 x + sin x / cos x = 0

Answer 1

Решение
(sin3x + sinx) / cosx = 0
(2*(sin(3x+x)/2)*cos(3x-x)/2) / cosx = 0
(sin4x)*(cosx) / cosx = 0
sin4x = 0
4x = πk, k∈Z
x = (1/4)*πk, k∈Z
cosx ≠ 0
x ≠ π/2 + πn, n∈Z