S contains mn, n = 1, 2, 3, 4, 5, 6, 7, 8
S = Earth; m1 = vs (voltage source); m2 = Rs (internal resistance of voltage source); m3 = Rin (amplifier as an equivalent load with respect to voltage source); m4 = Avin (voltage received by amplifier multiplied by amplifier's gain (A)); m5 = Rout (internal resistance of amplifier); m6 = RL (load resistance); m7 = conducting wire; m8 = simple voltage amplifier.
Given figure 8.1.3:
Show that vL = Avs
When Rin is very large and Rout is very small.