# Science:Math Exam Resources/Courses/MATH100/December 2015/Question 10 (c)/Hint 1

If ${\displaystyle \lim _{x\to +\infty }f(x)=c}$ or ${\displaystyle \lim _{x\to -\infty }f(x)=c}$, then the horizontal line ${\displaystyle y=c}$ is a horizontal asymptote of the function.