All three problems can be solved with a very simple wiring change: Simply disconnect the
node between the two resistors labeled R1, node X, from ground. The circuit with this small
but functionally profound change is redrawn in Fig. 2.20(b), where we have lumped the two
resistors (R1 and R1) together into a single resistor (2R1).
Analysis of the circuit in Fig. 2.20(b), assuming ideal