\[\boxed{\text{1128.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
\[y = \sqrt{x}.\]
\[\textbf{а)}\ y = 2\sqrt{x}\]
\[\textbf{б)}\ y = - \sqrt{x}\]
\[\textbf{в)}\ y = \sqrt{- x}\]