(sin(2x+4x)+sin(2x-4x))/2=(sin(6x+8x)+sin(6x-8x))/2
sin6x-sin2x=sin14x-sin2x
sin6x-sin14x=0
2sin((6x-14x))/2 cos((6x+14x))/2=0
2sin(-4x)cos(10x)=0
-sin4x=0 cos10x=0
4x=пи n 10x=пи/2+пи n
x=пи/4*n x=пи/20+пи/10 n
