# Output Voltage Formula verification of Operational Amplifier circuit

I'm trying to built an op-amp circuit for a PT100 temperature sensor. I've found the following circuit diagram online (from a polish website): And I'm trying to find the formula for the output voltage as a function of the input voltage. I came up with the following formula (sorry, it's an image, no Latex here): Can someone please help me verify that the last formula expressing Vout as a function of Vin is correct? Thanks in advance

EDIT1: at the beginning of the demonstration, R1 and R2's values have been switched.

EDIT2: Please, this question IS NOT a duplicate of a previous question I've posted. In this question, I'm trying to verify that my computations are OK. In the other question I was trying to ask if it was common for Proteus to present results that slightly differ from the electric model.

• Possible duplicate of Difference between Proteus results and KCL-deduced formula – Kevin Kruse May 1 '19 at 19:43
• I think there is an error in the OpAmp law: $V_1 = V_2 = v$ should be $V_4 = V_2 = v$ – Huisman May 1 '19 at 19:59
• Rest of equations (including last steps) seem correct. Next step, expanding A and B. Good luck :) – Huisman May 1 '19 at 20:08
• @Huisman, you're right! but doesn't change the result! Thank you!! – N. Wells May 1 '19 at 20:25
• – JRE May 1 '19 at 20:56