Chapter 4, Problem 21P

For the circuit in Fig. P4.21,

(a) find $V_o$ in terms of $V_1$ and $V_2.$

(b) If $V_1=\text{2 V}$ and $V_2=\text{6 V}$ find $V_2.$

(c) If the op-amp supplies are $\pm \text{12 V}$, and $V_1=\text{4 V,}$ what is the allowable range of $V_2?$