Arccos(-√2/2)+arctg(-1)-2arcsin(-1/2)+3arcctg(-√3)=?

Question

Arccos(-√2/2)+arctg(-1)-2arcsin(-1/2)+3arcctg(-√3)=?

Answer 1

=(π-π/4)-π/4-2*(-π/6)+3(π-π/3)=

π/2+π/3+2π=5π/6+2π=17π/6