$\displaystyle 1 + \frac{2x^2+1}{x^4}$
$\displaystyle \frac{x^4}{x^4} + + \frac{2x^2+1}{x^4}$
$\displaystyle \frac{x^4+2x^2+1}{x^4}$
$\displaystyle \frac{(x^2+1)^2}{(x^2)^2}$
$\displaystyle \left(\frac{x^2+1}{x^2}\right)^2$
now put it all to the 1/8 power and finish it