Вычислить:
cos(-210)*sin330*tg120*ctg(-300)
Заранее спасибо!

cos(-210°)•sin(330°)•tg(120°)•ctg(-300°) = cos(210°)•sin(330°)•tg(120°)•(-ctg(300°)) = -cos(180°+30°)•sin(360°-30°)•tg(180°-60°)•ctg(360°-60°) = -(-cos(30°))•(-sin(30°))•(-tg(60°))•(-ctg(60°)) = -cos(30°)•sin(30°)•tg(60°)•ctg(60°) = -√3/2 • 1/2 • 1 = -✓3/4