Ответ: -1/2
tg(-17π/4) ⋅ sin(-25π/6) = -tg(17π/4) ⋅ (-sin(25π/6)) = tg(4π + π/4) ⋅ sin(4π + π/6) = tg(π/4) ⋅ sin(π/6) = 1 ⋅ (1/2) = 1/2
Ответ: 1/2