Arcsin 1/2+arctg 0+arccos(-1/2)

arcsin 1/2 + arctg 0 + arccos(-1/2) = arcsin 1/2 + arctg 0 + (Pi - arccos 1/2) = Pi/6 + 0 + Pi - Pi/3 = Pi/6 + 2Pi/3 = 5Pi/6