Форум ЗнаниО

Как можно решить. Cos x + cos 2 x = 1/2-sin2x

CosX + Cos^2X = (1/2) – Sin^2X.

CosX + Cos^2X + Sin^2X = 1/2.

CosX + 1 = 1/2.

CosX = -1/2.

X = (2 * π/3) + 2 * π * n, X = (4 * π/3) + 2 * π * n. n Є Z.