Cos3x/sin2x=1 при 170(градусов)<x<280(градусов)
Cos3x=sin2x cos3x-cos(π/2-2x)=0 -2sin(x/2+π/4)sin(5x/2-π/4)=0 sin(x/2+π/4)=0 x/2+π/4=πk x/2=-π/4+πk x=-π/2+2πk,k∈z sin(5x/2-π/4(=0 5x/2-π/4=πk 5x/2=π/4+πk x=π/10+2πk/5,k∈z