How do you find the vertical, horizontal or slant asymptotes for y = (8 x^2 + x - 2)/(x^2 + x - 72)y=8x2+x2x2+x72?

1 Answer
Oct 23, 2016

The vertical asymptotes are x=8x=8 and x=-9x=9
and the horizontal asymptote is y=8y=8

Explanation:

We start by factorising the denominator
x^2+x-72=(x-8)(x+9)x2+x72=(x8)(x+9)

As we cannot divide by so x!=8x8 and x!=-9x9
So the vertical asymptotes are x=8x=8 and x=-9x=9

As the degree of the polynomial of the numerator and denominator are the same, there is no slant asymptote.

To find the horizontal asymptote, we find the limit as x->+-oox±
We take the highest order of the polynomials

lim y=8/1
x->-oo

And
lim y=8/1
x->oo
So the horizontal asymptote is y=8