R1 note: 1) passive sign convention 2) each plot corresponds to a specific subcircuit vS + - A i + + vR - v - p3-8 revisited, repeat for Circuit B Rest of the circuit B Circuit A iA i iR i A + - + + vA - 1/R 1 R vS vS vR - vA R1 vR But iA= -i, so flip source over and use negative voltage i iA iS vA + i + iR A + R2 -v S v - -v S Rest of the circuit B vA Circuit B A Now let’s consider the output of the combined voltage source and resistor (note that I’ve flipped the reference on v to adhere to passive sign convention within the subcircuit). i R1 -v S + i - + vR - v + 1/R 1 vs/R1 v -v S v=0 when vR=vS Finally, let’s flip the reference direction on v to put the "the rest of the circuit" in terms of passive sign convention as viewed by the subcircuit. Thereby flipping the plot relative to the vertical axis. Confusing? Yep. Too many steps and lots of opportunity for mistakes. But you have to know how to manipulate plots. i R1 -v S + i + v - vs/R1 -1/R 1 vS v Starting from scratch, return to Circuit A at the top of this sheet, forgetting about the preceding plots. Determine what v leads to i=0, next find what i leads to v=0, finally plot these two points in the i-v plane (much easier).