I know I've had this post about Op Amp, but I wanted to start this again with fresh mind (also there is a lot of pages and it's hard to find the answears sorry).

About Op Amp.

I guess there are only 2 questions? So comming with the first one : Op Amp with only negative feedback simple inverting OpAmp.

It is known that giving Vin negative input will result in reverting the input. So Vin = 1V will result in Vout = -1V.

Also V- is equal = 0V so that V- is equal V+. But according to this : Vout = Aol(V+ - V-), the output should result in something different ? Like Vout= 0V ? More logical would be if V- = 1V so Vout = Aol(0 - 1V). It is probably wrong but it is important for next question !

Second question is for both feedbacks :

I've had from the last post all calculations I will post them here

Here there are calculations for Vx (which is here V+) that it is equal to V-. But for the first one the Vx is positive and for the other one the Vx is negative while Vin is constant 1V positive.

I've heard that it depends on the which feedback is "stronger". I've seen those equations for stronger feedbacks, but I don't understand it when I look att this equation : Vout = Aol(V+ - V-). Let's take aside this "stronger" feedback equations. Why V- and V+ can't be negative while Vin is positive ? the results mentions that they can be equal so it should work.

Also the next answear was also because I have connected Vin which was positive to positive input, and ?I mean why connecting Vin to positive input must result in positive output when V- and V+ is not defined ? Unknown values. For the first question it is also a good question. Why Vin defines the Output ? when Vout = Aol(V+ - V-) and V- = 0V ?

If something is not clear I'll try to write it better.