Question

Решить уравнение:
sin4x-sin7x=0

Answer 1

Решение
sin4x - sin7x = 0
2*[cos(4x + 7x)/2] * [sin(4x - 7x)/2] = 0
1)  cos(11x/2) = 0
11x/2 = π/2 + πn, n∈Z
x = π/11 + 2πn/11, n∈Z
2) sin(3/2x) = 0
3/2x = πk, k∈Z
x = 2πk/3, k∈Z