Question

1+2cos x=0 решить уровнение

Answer 1

Решение
1 + 2cosx = 0
cosx = - 1/2
x = (+ -)arccos(-1/2) + 2πk, k∈Z
x = (+ -)(π - arccos(1/2)) + 2πk, k∈Z
x = (+ -)(π - π/3) + 2πk, k∈Z
x = (+ -)(2π/3) + 2πk, k∈Z