cos(π - t) + cos(π/2 - t)/sin(2π - t) + sin(3π/2 - t) = -cost + sint/-sint - cost = cost - sint/cost + sint
tg(π - t) × sin(3π/2 + t)/cos(π + t) × tg(3π/2 + t) = -tgt × -cost/-cost × -ctgt = tgt/ctgt = tg^2 t
