9) - tg 150°. sin (-210°).cos 135°

- tg 150° ⋅ sin (-210°) ⋅ cos 135° =

= - tg (180° - 30°) ⋅ (-sin (210°)) ⋅ cos (90° + 45°) =

= -(-tg 30°) ⋅ (-(-sin 30°)) ⋅ (-sin 45°) =

= - tg 30° ⋅ sin 30° ⋅ sin 45° =

= - (1/√3) ⋅ (1/2) ⋅ (1/√2) = - (1/√3) ⋅ (1/2) ⋅ (√2/2) = - √2/(4√3) = - (√2 * √3)/(4√3 * √3) = -√6/12

Ответ: -√6/12