2sinxcocx/2cos²x * sinx/(1+cosx)=(1-sinx)/sinx
sin²x/cosx(1+cosx)=(1-sinx)/sinx
(1-cos²x)/cosx(1+cosx)=(1-sinx)/sinx
(1-cosx)(1+cosx)/cosx(1+cosx)=(1-sinx)/sinx
(1-cosx)/cosx=(1-sinx)/sinx
sinx(1-cosx)-cosx(1-sinx) sinx≠0 U cosx≠0
sinx-sinxcosx-cosx_sinxcosx=0
sinx-cosx=0
sinx-sin(π/2-x)=0
2sin(x-π/4)cosπ/4=0
sin(x-π/4)=0
x-π/4=πn
x=π/4+πn
x={-3π/4;π/4;5π/4;9π/4;13π/4;17π/4;21π/4;25π/4;29π/4}∈[-π;8π]-9корней