Please answer this two part question A) It is known that when an Op-amp is operated using the negative feedback configuration, the output impedance reduces. Derive an expression that proves this. B)...

Please answer this two part question

A) It is known that when an Op-amp is operated using the negative feedback
configuration, the output impedance reduces. Derive an expression that proves this.

B) It is known that when an Op-amp is operated using the positive feedback
configuration, the output impedance increase. Derive an expression that proves this.