Question

1) ctg п/3tg(-п/3)- cost(-п) sin п 2)tg 720+sin 540-ctg 135

Answer 1

1)cotgπ/3.tg(-π/3)-cos(-π).sinπ=√3/3.(-√3)-cosπ.0=-3/3-0=-1
   cotgπ/3=tgπ/6=√3/3, tg(-π/3)=-tgπ/3=-√3, cos(-π)=cosπ=-1,sinπ=0
2)tg720°+sin540°-cotg135°=tg(0°+4.180°)+sin(360°+180°)-cotg(-45°+180°)=tg0°+sin180°-cotg(-45°)=0+0+1=1