curation and difference amplifier (6 pts) 1) ( pts) Express vo as a function of v, and v2 for the following circuit shown in Fig. 4.1 2) 3 pts) What is the input resistance seen by v, alone (Fig. 4.2)? By v2 alone (Fig. 4.3)? By a source connected between the two input terminals (Fig. 4.4 Fig. 4.1 Fig. 4.2 Fig. 4.4 Fig. 4.3