Question

arcсtg(-√3/3)-arcsin 0+arcсos(-1/2)=

Answer 1

$arcctg(- frac{ sqrt{3} }{3})- arcsin0+arccos(- frac{1}{2}) =( pi - arcctg( frac{ sqrt{3} }{3})-\- 0 + ( pi - arccos( frac{1}{2}) = ( pi - frac{ pi }{3}) + ( pi - frac{ pi }{3} )= 2 pi - frac{2 pi }{3} =\= frac{6pi-2pi}{3} = frac{4pi}{3}$