Ответ:
g'(x) =
\\ \frac{8}{ {x}^{2} } = 4 \\ 4 {x}^{2} = 8 \\ {x}^{2} = 2 \\ x = + - \sqrt{2} " alt="4 - \frac{8}{ {x}^{2} } = 0 = > \\ \frac{8}{ {x}^{2} } = 4 \\ 4 {x}^{2} = 8 \\ {x}^{2} = 2 \\ x = + - \sqrt{2} " align="absmiddle" class="latex-formula">