(a) If $\left\{a_{n}\right\}$ is convergent, show that
$$\lim _{n \rightarrow \infty} a_{n+1}=\lim _{n \rightarrow \infty} a_{n}$$
$\begin{array}{l}{\text { (b) A sequence }\left\{a_{n}\right\} \text { is defined by } a_{1}=1 \text { and }} \\ {a_{n+1}=1 /\left(1+a_{n}\right) \text { for } n \geqslant 1 . \text { Assuming that }\left\{a_{n}\right\} \text { is }} \\ {\text { convergent find its limit }}\end{array}$