\[y = \sqrt{2x - x^{2}}\]
\[2x - x^{2} \geq 0\]
\[x^{2} - 2x \leq 0\]
\[x(x - 2) \leq 0\]
\[0 \leq x \leq 2.\]
\[Ответ:0 \leq x \leq 2.\ \]