Sinx/4=-1/2 sin(x/2-П/4)= -Корень из 3/2
1 sinx/4=-1/2 x/4=(-1)^(n+1)*π/6+πn x=(-1)^(n+1)*2π/3+4πn,n∈z 2 sin(x/2-π/4)=-√3/2 x/2-π/4=4π/3+2πn U x/2-π/4=5π/3+2πn x/2=19π/12+2πn U x/2=23π/12+2πn x=-19π/6+4πn U x=23π/6+4πn,n∈z