Difference between revisions of "TF ErrorAna PropOfErr"

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<math>f(x) = f(a) + f^{\prime}(x)|_{x=a} \frac{x}{1!} + f^{\prime \prime}(x)|_{x=a} \frac{x^2}{2!} + ...</math>
 
<math>f(x) = f(a) + f^{\prime}(x)|_{x=a} \frac{x}{1!} + f^{\prime \prime}(x)|_{x=a} \frac{x^2}{2!} + ...</math>
 
;<math>= \sum_{n=0}^{infty} f^{(n)}(x)|_{x=a} \frac{x^n}{n!}</math>
 
;<math>= \sum_{n=0}^{infty} f^{(n)}(x)|_{x=a} \frac{x^n}{n!}</math>
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 +
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For small values of x we can expand functions about 0 such that
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\sqrt(1+x) = \sqrt(1-0) | (1+x)^{-1/2}

Revision as of 19:58, 9 January 2010

A quantity which is calculated using quantities with known uncertainties will have an uncertainty based upon the uncertainty of the quantities used in the calculation.

To determine the uncertainty in a quantity which is a function of other quantities, you can consider the dependence of these quantities in terms of a tayler expansion

Consider a calculation of a Table's Area

[math]A= L \times W[/math]

The mean that the Area (A) is a function of the Length (L) and the Width (W) of the table.

[math]A = f(L,W)[/math]


The Taylor series expansion of a function f(x) about the point a is given as

[math]f(x) = f(a) + f^{\prime}(x)|_{x=a} \frac{x}{1!} + f^{\prime \prime}(x)|_{x=a} \frac{x^2}{2!} + ...[/math]

[math]= \sum_{n=0}^{infty} f^{(n)}(x)|_{x=a} \frac{x^n}{n!}[/math]


For small values of x we can expand functions about 0 such that

\sqrt(1+x) = \sqrt(1-0) | (1+x)^{-1/2}