Ответ:

[tex]11 \sqrt{3} \tan \frac{7\pi}{6} \times \cos \frac{4\pi}{3} = 11 \sqrt{3} \tan \frac{\pi}{6} \times ( - \frac{1}{2}) = 11 \sqrt{3} \times \frac{ \sqrt{3} }{3} \times ( - \frac{1}{2} ) = - \frac{33}{6} = - \frac{11}{2} = - 5.5[/tex]

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