Решите уравнение sinx*cosx+sin2x*cosx=0

Sinxcosx+sin2xcosx=0
sinxcosx+2sinx.cosx.cosx=0
sinxcosx(1+2.cosx)=0
a)sinx=0, x=k.π
b)cosx=0,x=π/2+k.π
c)1+2.cosx=0, cosx=-1/2
   x=2π/3+2k.π
   x=4π/3+2k.π
k∈Z