Cosx/2=-1/2 решите друзья

Question

Cosx/2=-1/2 решите друзья

Answer 1

Cosx/2=-1/2
Cox/3=4п/3
СOS X=4p
-/+arccos 4p+2pn

Answer 2

CosX/2=-1/2
cosX=-1
X=180°