Ответ:

[tex]2tg\frac{\pi }{3} *ctg(-\frac{\pi }{6})+cos\pi -2sin\frac{\pi }{4} = 2*\sqrt{3}*(-\sqrt{3} ) + (-1)-2*\frac{\sqrt{2} }{2} = -6-1-\sqrt{2} = -7-\sqrt{2}[/tex]