Cos9*x-cos5*x=√3sin2*x

Cos(9x) - cos(5x) = √3sin(2x);-2sin((9x + 5x)/2)·sin((9x - 5x)/2) + √3·sin(2x) = 0;-2sin(7x)·sin(2x) + √3·sin(2x )= 0;sin(2x)(√3 - 2sin(7x))= 0;1. sin(2x) = 0;2x = пn;x = пn/2;2. (√3 - 2sin(7x))= 0;sin(7x) = √3/2;7x = п/3 + 2пn;7x = 2п/3 + 2пn;x = (-1)^n ·(п/21) + пn/7;