\[y = \frac{8}{\sqrt{12 + x - x^{2}}}\]
\[12 + x - x^{2} > 0\]
\[x^{2} - x - 12 < 0\]
\[x_{1} + x_{2} = 1;\ \ x_{1} \cdot x_{2} = - 12\]
\[x_{1} = 4;\ \ \ x_{2} = - 3;\]
\[(x + 3)(x - 4) < 0\]
\[- 3 < x < 4.\]