\frac{\pi}{4}\\\\\frac{x^2-x-6}{x^2-9}<1\\\\\frac{x^2-x-6-x^2+9}{(x-3)(x+3)}<0\\\\\frac{-(x-3)}{(x-3)(x+3)}<0\\\\\frac{1}{x+3}>0\\\\1>0,\; x+3>0\; \; \to \; \; x>-3\\\\x\in (-3,+\infty)" alt="arccos\frac{1}{\sqrt2}=\frac{\pi}{4}\approx 0,785<1\\\\(\frac{\pi}{4})^{{\frac{x^2-x-6}{x^2-9}}}>\frac{\pi}{4}\\\\\frac{x^2-x-6}{x^2-9}<1\\\\\frac{x^2-x-6-x^2+9}{(x-3)(x+3)}<0\\\\\frac{-(x-3)}{(x-3)(x+3)}<0\\\\\frac{1}{x+3}>0\\\\1>0,\; x+3>0\; \; \to \; \; x>-3\\\\x\in (-3,+\infty)" align="absmiddle" class="latex-formula">