a. Assuming that $\lim _{n \rightarrow \infty}\left(1 / n^{f}\right)=0$ if $c$ is any positive constant, show that
$$\lim _{n \rightarrow \infty} \frac{\ln n}{n^{f}}=0$$
if $c$ is any positive constant.
b. Prove that $\lim _{n \rightarrow \infty}\left(1 / n^{\circ}\right)=0$ if $c$ is any positive constant.
(Hint: If $\epsilon=0.001$ and $c=0.04,$ how large should $N$ be to
ensure that $\left|1 / n^{r}-0\right|<\epsilon$ if $n>N ? )$