[tex]\displaystyle\bf\\\Bigg(tg\frac{\pi }{6} \Bigg)^{-x^{2} } \geq \Bigg(tg\frac{\pi }{6} \Bigg)^{9} \\\\\\tg\frac{\pi }{6} =\frac{\sqrt{3} }{3} \\\\\\0 < \frac{\sqrt{3} }{3} < 1 \ \Rightarrow \ \ -x^{2} \leq 9\\\\x^{2} \geq -9\\\\Otvet \ : \ x\in\Big(-\infty \ ; \ +\infty\Big)[/tex]