\[y = 1 + 5\sqrt{x^{2} + 9}\]
\[f(x) - четная,\ \ \ \ \ x_{\min} = 0\]
\[y(0) = 1 + 5\sqrt{0 + 9} =\]
\[= 1 + 5\sqrt{9} = 1 + 5 \cdot 3 =\]
\[= 1 + 15 = 16\]
\[y_{\min} = 16 \Longrightarrow достигается\ при\]
\[\ x_{\min} = 0.\]
\[Ответ:y = 16\ \ при\ x = 0.\]