Решите уравнение sin2x+2cos^2x=0

sin2x+2cos²x=0 2sinxcosx+2cos²x=0 2cosx(sinx+cosx)=0 cosx=0                   или         sinx+cosx=0|:cosx≠0 x=π/2+πn, n∈Z                     tgx+1=0                                               tgx=-1                                               x=-π/4+πn, n∈Z