) arctg √3 = π/3 arctg1 = π/4 arcctg (-√3) = π- arcctg √3 = π- π/6 = 5 π/6 получается arctg √3 - arctg1 + arcctg (-√3) = π/3- π/4+ 5π/6 = (4π-3π+10π)/12 = 11π/12 2) arcctg √3/3= π/6 tg (arcctg √3/3)=tg ( π/6)= 1/ √33) arcctg (sin π/2) = arcctg 1 = π/4