2π.
Пошаговое объяснение:
-4•arcsin (-√2/2) + 8 arccos (- √2/2) - 15 arcctg √3/3 = + 4•arcsin (√2/2) + 8•(π - arccos (√2/2) -15• arcctg (√3/3) = 4•π/4 + 8•(π - π/4) - 15•π/3 = π + 8•3π/4 - 5π = π + 6π - 5π = 2π.
