How do you find the end behavior of f(x)= (3x+1)/x?

1 Answer
Jan 11, 2016

lim_(x rarr -oo)(3x+1)/x=3

lim_(x rarr +oo)(3x+1)/x=3

:. y=3 horizontal asymptote

Explanation:

To find the end behavior of f(x) you have to evaluate:

lim_(x rarr +-oo) f(x)

  1. lim_(x rarr -oo)(3x+1)/x~~lim_(x rarr -oo)(3x)/x=3

  2. lim_(x rarr +oo)(3x+1)/x~~lim_(x rarr +oo)(3x)/x=3

Therefore

y=3 is an horizontal asymptote

graph{(3x-1)/x [-8.72, 7.08, -1.28, 6.62]}