Question

12arccos корень(3)|2 - 3arccos(-1|2)

Answer 1

arccos(√3/2)=π/6
arccos(-1/2)=π-arccos(1/2)=π-(π/6)=5π/6

12·arccos (√3/2) - 3·arccos(-1/2)=12·(π/6) - 3·(5π/6)=-3π/6=-π/2