What is the best way to find an oblique asymptope of a curve

I know how to find the horizontal asymptopes, but whats the best way to find an oblique asymptope thats relatively simple?

An example curve you could do it on would be y^2 = x^4/(x^2) - 1

Thanks!

The best way to find the slant asymptote is through polynomial division.

........... 1x^2 ................ 1
.......... ____________________________
(x² - 1) | 1x^4 .... 0x^3 .... 0x^2 ... 0x .... 0
......... | -1x^4 ............... +1x^2
......... | ---------------------------------
......... | ........................ 1x^2 ............. 0
......... | ....................... -1x^2 ........... +1
......... | ....................... -------------------------
......... | ........................................… 1

You ignore the remainder, and just write the stuff on top: y² = x² + 1. Therefore, the equation(s) of the asymptote(s) is/are y = ±√(x² + 1)