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1. Derive the voltage gain $A_{\rm V}= {{U_{\rm O}}\over{U_{\rm I}}}$ for the inverting amplifier. \\
Use the procedure that was used for the non-inverting amplifier.\\
* What is looking for?
* Number of variables?
* Number of necessary equations?
* Establishing the known equations
* Derivation of the voltage gain
Take into account that for the differential gain $A_\rm D$ of the ideal OPV applies: $A_\rm D \rightarrow \infty$. And the following also applies: $1/A_\rm D \rightarrow 0$ \\
**But** the following doesn't always apply: ${{C}\over{U_x \cdot A_\rm D}} \rightarrow 0$, for an unknown constant $C$ and a voltage $U_x$!
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2. Which type of amplifier circuit (inverting or non-inverting amplifier) has the lower input resistance? Why?