$${ a }^{ 2 } + \frac { 1 } { { a }^{ 2 } } =3$$
$a=\frac{-\sqrt{5}-1}{2}\approx -1.618033989$
$a = \frac{\sqrt{5} + 1}{2} \approx 1.618033989$
$a=\frac{\sqrt{5}-1}{2}\approx 0.618033989$
$a=\frac{1-\sqrt{5}}{2}\approx -0.618033989$