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Enter two measurements with their uncertainties and pick an operation to see the propagated uncertainty in the result - the calculation behind every lab report's error-analysis section.
Updates live as you typeEnter your measurements to see the result.
Lab report material is exactly the kind of dense, formula-heavy content spaced repetition was built for - Encodr resurfaces it before the next problem set, not the night before.
Get started freeFor addition or subtraction, absolute uncertainties add in quadrature:
δz = √(δx² + δy²). For multiplication or division,
relative uncertainties add in quadrature instead:
δz/z = √((δx/x)² + (δy/y)²), then that relative
uncertainty is scaled back up by the result to get an absolute uncertainty again. Both formulas
assume the uncertainties in x and y are independent and random, which is the standard assumption
for a single-trial measurement uncertainty (not a full statistical treatment of repeated trials,
which uses standard error instead). This is the same method behind the propagated-uncertainty
section of a typical physics or chemistry lab report.
The two formulas behind every error-analysis section: one for addition and subtraction, one for multiplication and division.
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