ПОМОГИТЕ!!!!!!!!!! sinx+sin2x+sin3x+sin4x=0

sinx+sin2x+sin3x+sin4x=0(sinx+sin4x)+(sin2x+sin3x)=02sin(5x/2)cos(3x/2)+2sin(5x/2)cos(x/2)=0|:2sin(5x/2)(cos(3x/2)+cos(x/2))=0sin(5x/2)*2cos(x)*cos(x/2)=01) sin(5x/2)=05x/2=πnx=(2πn)/5,n∈Z.2) cosx=0x=(π/2)+πn,n∈Z.3) cos(x/2)=0x/2=(π/2)+πnx=π+2πn,n∈Z.