Find the resistance and capacitance in Wien bridge

The Electrician said:

By the way, using Maple (or similar package) would have avoided the error you made in your four lines of simple algebra (I think it's just a sign error).

That's one of the advantages to using what I sometimes see called a "math assistant". The silly algebra mistakes are avoided. Real world problems are usually bigger than this one and I very much appreciate the handing over of the drudgery of much algebra to my computer.

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A sanity check on my part (which I did not do in this case, which I should have) would have raised the question of whether it really is possible to get a negative resistance for R3. Since choosing R1 to be very small but R2 to be much larger than the reciprocal of R2 would do this, it strongly suggests something wrong in the work.

In reviewing my scratch paper, there is nothing wrong. The error came in transcribing the result of the "four lines" into tex where I erroneously put a negative sign between the two RC terms. After that, all of the work was done directly in tex in the post dialog box.

Highlights the rule -- always, always, ALWAYS ask if the answer makes sense. I failed to do that and go burned.