Consider the difference-amplifier circuit of Fig. 2.16 for the case R1 = R3 = 2 kΩ and R2 = R4 =
200 kΩ. (a) Find the value of the differential gain Ad. (b) Find the value of the differential input
resistance Rid and the output resistance Ro. (c) If the resistors have 1% tolerance (i.e., each can be
within ±1% of its nominal value), use Eq.