(a) For the $T$ network in Fig. 18.97 , show that the $h$ parameters are:
\[
\begin{array}{c}
\mathbf{h}_{11}=R_{1}+\frac{R_{2} R_{3}}{R_{1}+R_{3}}, \quad \mathbf{h}_{12}=\frac{R_{2}}{R_{2}+R_{3}} \\
\mathbf{h}_{21}=-\frac{R_{2}}{R_{2}+R_{3}}, \quad \mathbf{h}_{22}=\frac{1}{R_{2}+R_{3}}
\end{array}
\]
(b) For the same network, show that the transmission parameters are:
\[
\begin{array}{c}
\mathbf{A}=1+\frac{R_{1}}{R_{2}}, \quad \mathbf{B}=R_{3}+\frac{R_{1}}{R_{2}}\left(R_{2}+R_{3}\right) \\
\mathbf{C}=\frac{1}{R_{2}}, \quad \mathbf{D}=1+\frac{R_{3}}{R_{2}}
\end{array}
\]