\[y = \sqrt{x^{2} - 2x - 48}\]
\[x^{2} - 2x - 48 \geq 0\]
\[x^{2} - 2x - 48 = 0\]
\[x_{1} + x_{2} = 2,\ \ x_{1} = 8\]
\[x_{1} \cdot x_{2} = - 48,\ \ x_{2} = - 6\]
\[Ответ:( - \infty;\ - 6\rbrack \cup \lbrack 8; + \infty).\]