tg(2pi-x)cos(3pi/2+2x)=sin(-pi/2) [2pi;7pi/2]
tg(2π–x)=-tgx cos(3π/2+2x)=sin2x sin(–π/2)=-1 -tgx*(2sinx*cosx)=-1 cosx≠ 0 2sin^2x=1 sinx= ± 1/sqrt(2) x= ±(π/4)+πk, k ∈ Zπ б)(π/4)+2π=9π/4 (3π/4)+2π=11π/4 (5π/4)+2π=13π/4