Assignment problem on Operational Amplifier

[lawteoh777]

The question is as given in the image attached entitled 'amplifier question' I would just like someone to check my working and verify whether it's correct or not. Thanks. And also want to ask on the second part which is 'what mathematical operation does this circuit perform?' Any help would be really appreciated.



Relevant equations would be V+ = V- I guess.



The attempt on my question is as attached in the image entitled 'amplifier question 2'

 

[berkeman]

The question is as given in the image attached entitled 'amplifier question' I would just like someone to check my working and verify whether it's correct or not. Thanks. And also want to ask on the second part which is 'what mathematical operation does this circuit perform?' Any help would be really appreciated.



Relevant equations would be V+ = V- I guess.



The attempt on my question is as attached in the image entitled 'amplifier question 2'

Your work looks correct to me. And for the second part of the question, what does the equation V = (V1 + V2)/2 look like to you? It should be the form of a familiar operation...

And the gain afterwards (from the output resistors) is just gain on top of the original operation.

 

[lawteoh777]

Really no idea on what the equation V = (V1 + V2)/2 looks like to me. It looks like average potential difference, but it doesn't make sense also. :/

 

[berkeman]

Really no idea on what the equation V = (V1 + V2)/2 looks like to me. It looks like average potential difference, but it doesn't make sense also. :/

That's what I would have called it, an average voltage. With gain afterwards. Not sure if it has a catchier name...