A series-shunt feedback amplifier employs a basic amplifier with input and output resistances each of $2 \mathrm{k} \Omega$ and $\operatorname{gain} A=1000 \mathrm{V} / \mathrm{V}$. The feedback factor $\beta=0.1 \mathrm{VN}$. Find
the gain $A_{n}$ the input resistance $R_{r}$, and the output recistanse $R_{v f}$ of the closed-loop amplifier.