ruslank1460

arctg(-1) + 2arccos (-√2/2) - arcsin 1/2 = -arctg(1) + 2(π - arccos (√2/2)) - arcsin 1/2 = -π/4 + 2(π - π/4) - π/6 = -π/4 + 3π/2 - π/6 = 13π/12