Why does arccos (-1/2) equal to pi - arccos(1/2)? - Quora
SOLVED: Q2 a) Find the exact value of each expression, if possible, without using a calculator: (i) arcsin(1/2) (ii) arccos(2/3) (iii) arctan(1) (iv) arccos(-1/2) (v) arcsin(1) (vi) arctan(1/2) (vii) arccos(-1) (viii) arcsin(1/√2) (