What are the asymptotes of f(x)=-x/((x-1)(3-x)) ?

1 Answer
Oct 28, 2016

f(x) has the following asymptotes:
Vertical at x=1 and x=3
Horizontal at y=0 as x->oo and at y=0 as x->-oo

Explanation:

f(x)=-x/((x-1)(3-x))

We will have vertical asymptotes when the denominator is zero,
ie
(x-1)(3-x) = 0 => x=1,3

As x->oo => f(x) ~-x/(x(-x)),
ie f(x) ~1/x->0^+

Similarly, As x->-oo => f(x) -> 0^-,

f(x) has the following asymptotes:
Vertical at x=1 and x=3
Horizontal at y=0 as x->oo and at y=0 as x->-oo

graph{-x/((x-1)(3-x)) [-10, 10, -5, 5]}