Question

COS(2X/3 ПИ)=1 CРОЧНО!!!!!

Answer 1

$cos\frac{2x}{3}\pi =1\\\\\frac{2x}{3}\pi =2\pi n,\; n\in Z\\\\x=\frac{3}{2\pi }\cdot 2\pi n=3n,\; n\in Z$