Calculating uncertainty of a function in Mathematica

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SUMMARY

The forum discussion focuses on calculating uncertainty in a function using Mathematica. A user encountered an issue where the calculated uncertainty was incorrectly scaled by a factor of 10^7. Another participant identified the problem as a misapplication of the error propagation formula, specifically noting that the standard deviation (SDx) terms were not correctly included in the calculations. The correct formula involves using SDx² multiplied by the squared derivative (df/dx)² for each term, including squaring the term for R.

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Shukie
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I have a function of which I'm trying to determine the uncertainty. I'm using Mathematica and I can't get it to work. However, I don't see what I'm doing wrong. My uncertainty has the same value as the function itself, only a factor 10^7 higher. That is of course completely wrong, but I don't see where I'm going wrong. Could anyone please take a look?

http://home.orange.nl/~kuip3148/Differentieermethode.nb
 
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Hi Shukie,

This is probably a little late, but your formula for the propagation of errors is wrong. Each term should be of the form SDx²(df/dx)² where SDx is the standard deviation of x. You calculate the (df/dx)² part of each term but never use the SDx² part. Also, you forgot to square the one for R.
 

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