In the circuit shown in Eigure P6 .32, assume:
$$
\begin{aligned}
& E_n=1.3 \mathrm{~V} \quad D_n=1.9 \mathrm{~V} \\
& R_1=R_2=4.7 \mathrm{k} \Omega \\
& R_3=R_4=10 \mathrm{k} \Omega \quad R_a=1.8 \mathrm{k} \Omega
\end{aligned}
$$
Determine:
a. The output voltage $v_o$.
b. The common-mode component of $v_o$.
c. The difference-mode component of $v_o$.