Answer
$\bf{L}$ ; $\bf{x}$ ;
Horizontal asymptote
Work Step by Step
Let us consider that the function $f(x)$ is defined om some interval $(a, \infty)$.
Then , we have $\lim\limits_{n\to \infty} f(x)=L$
This implies that the value of the function $f(x)$ can be defined arbitrarily close to the limit $\bf{L}$ by taking $\bf{x}$ sufficiently large.
Then, the line $y=L$ is called a horizontal asymptote of the function $y=f(x)$
