Ответ: tg(α)sin(α) - 1/cos(α)
tg(-α) ⋅ sin(-α) - 1/cos α = -tg(α) ⋅ (-sin(α)) - 1/cos α = tg(α) sin(α) - 1/cos α
Ответ: tg(α) sin(α) - 1/cos(α)