\(\left\{{}\begin{matrix}\sqrt{x-2\sqrt{x-1}}\ne0\\x-2\sqrt{x-1}\ge0\\x-1\ge0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x\ne2\\\left(\sqrt{x-1}-1\right)^2\ge0\\x\ge1\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x\ne2\\x\in R\\x\ge1\end{matrix}\right.\)
\(\Rightarrow TXĐ:D=[1;+\infty)\cup\left\{2\right\}\)