What determines a horizontal asymptote? Calculus Limits Limits at Infinity and Horizontal Asymptotes 1 Answer Wataru Oct 10, 2014 Definition The line #y=b# is called a horizontal asymptote of #f# if at least one of the following limits holds: #lim_{x to -infty}f(x)=b# or #lim_{x to infty}f(x)=b#. I hope that this was helpful. Answer link Related questions What kind of functions have horizontal asymptotes? How do you find horizontal asymptotes for #f(x) = arctan(x)# ? How do you find the horizontal asymptote of a curve? How do you find the horizontal asymptote of the graph of #y=(-2x^6+5x+8)/(8x^6+6x+5)# ? How do you find the horizontal asymptote of the graph of #y=(-4x^6+6x+3)/(8x^6+9x+3)# ? How do you find the horizontal asymptote of the graph of y=3x^6-7x+10/8x^5+9x+10? How do you find the horizontal asymptote of the graph of #y=6x^2# ? How can i find horizontal asymptote? How do you find horizontal asymptotes using limits? What are all horizontal asymptotes of the graph #y=(5+2^x)/(1-2^x)# ? See all questions in Limits at Infinity and Horizontal Asymptotes Impact of this question 1868 views around the world You can reuse this answer Creative Commons License