How do you identify all asymptotes or holes for f(x)=(-2x^2-6x-4)/(x^2+x)?

1 Answer
Feb 25, 2017

The vertical asymptote is x=0
The horizontal asymptote is y=-2
There is a hole at x=-1
No slant asymptote

Explanation:

Let's factorise the denominator and the numerator

x^2+x=x(x+1)

-2x^2-6x-4=-2(x^2+3x+2)=-2(x+1)(x+2)

Therefore,

f(x)=(-2x^2-6x-4)/(x^2+x)=(-2cancel(x+1)(x+2))/(xcancel(x+1))

There is a hole at x=-1

As we cannot divide by 0, x!=0

The vertical asymptote is x=0

The degree of the numerator = the degree of the denominator, there is no slant asymptote.

lim_(x->+-oo)f(x)=lim_(x->+-oo)(-2x)/x=-2

The horizontal asymptote is y=-2

graph{(y+2(x+2)/(x))(y+2)=0 [-20.28, 20.27, -10.14, 10.14]}