I'm trying to understand the purpose of the capacitor C which is in parallel with the resistor R3. Current sources IB are indicative of the current offset which was the part of the lecture we had where we tried to compensate the offsets and the op amp is ideal.
When analyzing the DC regime the capacitor is an open circuit and all of current IB goes through the resistor R3 and when analyzing the AC regime it's a short circuit and no current passes through it.
Was it it's sole purpose to short-circuit the R3 resistor? Why would that be so important if that's the case other than reducing the total resistance of the circuit?
The capacitors are thought of as having infinite capacitance and IBs are DC current sources.