How to find the asymptotes of f(x) = (x+3) /( x^2 + 8x + 15)f(x)=x+3x2+8x+15 ?

1 Answer
Feb 28, 2016

Simplify f(x)f(x) to see that there is a horizontal asymptote y=0y=0, vertical asymptote x=-5x=5 and hole (removable singularity) at (-3, 1/2)(3,12)

Explanation:

f(x) = (x+3)/(x^2+8x+15)f(x)=x+3x2+8x+15

=(x+3)/((x+3)(x+5))=x+3(x+3)(x+5)

=1/(x+5)=1x+5

with exclusion x != -3x3

This function has horizontal asymptote y=0y=0 since 1/(x+5)->01x+50 as x->+-oo#

It has a vertical asymptote x=-5x=5, where the denominator is zero, but the numerator non-zero.

It has a hole (removable singularity) at (-3, 1/2)(3,12) since the left and right limits exist at (-3, 1/2)(3,12) and are equal.