Question

Помогите решить пж cox2x+sinx=0

Answer 1

$cos(2x) + sin(x) = 0 \ 1 - 2 sin(x)^{2} + sin(x) = 0 \ 1 - 2t ^{2} + t = 0 \ \ t = 1 \ t = - frac{1}{2} \ \ sin(x) = 1 \ sin(x) = - frac{1}{2} \ \ x = frac{pi}{2} + 2kpi \ x = frac{11pi}{6} + 2kpi \ x = frac{7pi}{6} + 2kpi \ \ OTBET: x = frac{pi}{2} + frac{2kpi}{3}$