1) tg(π-α)=-tga;

2) ctg(π+α)=ctga;

3) sin (360°+α)=sina;

4) cos (360°-α)=cosa;

5) ctg (360°-α)=-ctga;

2.

=-ctga*(-ctga)+ctga*tga=1-ctg^2 a

1) -tg α;

2) ctg α;

3) sin α;

4) cos α;

5)- ctg α;

1) tg(π/2+α)ctg(π-α)-ctg(π+α)ctg(π/2-α)=-ctg α (-ctg α)-ctg α tgα=