Closed Loop Gain = Vout/Vin = -R2/R1
In this case Vout/Vin = -10
It is called "inverting" due to the "-" sign in the output voltage. In other words, input and output have a 180ยบ phase shift.
This examples assume a "infinite" gain A. This configuration is said to change the infinite gain A for acurracy in selecting the gain.
