What are the asymptotes of f(x)=-x/((x^2-8)(x-2)) ?

1 Answer
Oct 25, 2016

the asymptotes are;
Vertical at x=-sqrt(8),2,sqrt(8)
Horizontal at 0 as x->+-oo

Explanation:

f(x)=x/((x^2-8)(x-2))
:. f(x)=x/((x^2-sqrt(8)^2)(x-2))
:. f(x)=x/((x+sqrt(8))(x-sqrt(8))(x-2))
So these will be vertical asymptotes.

So we can see that the denominator is zero when x=-sqrt(8),2,sqrt(8)

Also We have f(x)=x/(x^3 + "lower terms")
So as x->+-oo => f(x)->0

Hence, the asymptotes are;
Vertical at x=-sqrt(8),2,sqrt(8)
Horizontal at 0 as x->+-oo

The graph will help to visualise the results;
graph{x/((x^2-8)(x-2)) [-10, 10, -5, 5]}