Arcctg(-корень из 3) + arctg 1= ??? Help please :))

Question

Arcctg(-корень из 3) + arctg 1= ???
Help please :))

Answer 1

=(Π-arcctg√3)+arctg1=(Π-π/6)+π/4=5π/6+π/4=10π/12+3π/12=13π/12