解答

$${y=\sqrt{x}\log x}$$

$$\begin{eqnarray*} y'&=&\left(\sqrt{x}\right)'\log x+\sqrt{x}\left(\log x\right)... ...x+\sqrt{x}\times\frac{1}{x}\\ &=&\frac{1}{2\sqrt{x}}(2+\log x) \end{eqnarray*}$$