\[f(x) = \sqrt{x - \frac{8}{x - 2}}\]
\[x^{\backslash x - 2} - \frac{8}{x - 2} \geq 0;\ \ x \neq 2\]
\[\frac{x^{2} - 2x - 8}{x - 2} \geq 0\]
\[x^{2} - 2x - 8 = (x + 2)(x - 4)\]
\[D_{1} = 1 + 8 = 9\]
\[x_{1} = 1 + 3 = 4;\]
\[x_{2} = 1 - 3 = - 2;\]
\[\frac{(x + 2)(x - 4)}{x - 2} \geq 0\]
\[- 2 \leq x < 2;x \geq 4.\]
\[Ответ:\ - 2 \leq x < 2;x \geq 4.\]