$${ x }^{ 2 } + \frac{ 1 }{ { x }^{ 2 } } =16$$
$x=\frac{-\sqrt{14}-3\sqrt{2}}{2}\approx -3.992149037$
$x = \frac{\sqrt{14} + 3 \sqrt{2}}{2} \approx 3.992149037$
$x=\frac{3\sqrt{2}-\sqrt{14}}{2}\approx 0.25049165$
$x=\frac{\sqrt{14}-3\sqrt{2}}{2}\approx -0.25049165$
