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