Theorem 1 states that if $\lim _{x \rightarrow \infty} f(x)=L,$ then the sequence $a_{n}=$ $f(n)$ converges and $\lim _{n \rightarrow \infty} a_{n}=L .$ Show that the converse is false. In other words, find a function $f(x)$ such that $a_{n}=f(n)$ converges but $\lim _{x \rightarrow \infty} f(x)$ does not exist.