8) 2 arccos(1/2) + arctg(-1/√3) + arcsin(-√2/2)

2 arccos(1/2) + arctg(-1/√3) + arcsin(-√2/2) = 2 * π/3 - π/6 - π/4 = (8π - 2π - 3π)/12 = 3π/12 = π/4 Пояснение: arccos(1/2) = π/3 arctg(-1/√3) = -π/6 arcsin(-√2/2) = -π/4 Таким образом, 2 arccos(1/2) + arctg(-1/√3) + arcsin(-√2/2) = 2 * π/3 - π/6 - π/4 = (8π - 2π - 3π)/12 = 3π/12 = π/4