Question 143960
{{{4/x^4-5/x^2+1=0}}}
{{{4/x^2-5+x^2=0}}}
{{{4-5x^2+x^4=0}}}
(x^2-1)(x^2-4)=0

Implies x= +/- 1 or x=+/-2

{{{graph( 300, 200, -5, 5, -5, 5, 4/x^4-5/x^2+1)}}}

Notice the intersections.