tg(п-x)cos(3п\2-2х)=sin5п\6
tg(π-x)cos(3π/2-2x)=sin(5π/6); (x ≠ π/2+kπ, k ∈ Z) -tg(x)*(-sin(2x))=1/2 (sin(x))/(cos(x))*2sin(x)*cos(x)=1/2 sin(x)*2sin(x)=1/2 2sin(x)^2=1/2 sin(x)^2=1/4 sin(x)= ± 1/2