Вычислить
tg(-п/3) ctg п/6 - 2sin 3п/2 + cos (-п/3)

tg(-п/3) ctg п/6 - 2sin 3п/2 + cos (-п/3)=

-tg(π/3) ctg π/6 + 2sin π/2 + cos (π/3)=

-√3*√3+2*1+1/2=-3+2,5=1/2;