Finding A Relative Condition Number

In summary, the conversation discusses the relative condition number for the function f(x)=sqrt(x+1)-sqrt(x). The equation for the relative condition number is given, but it is noted that the limit is on ##\delta x##, not x. The concept of relative condition number is defined as the ratio of the change in output to the change in input of a function.
  • #1
ver_mathstats
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Homework Statement
Find the relative condition number for f(x)=sqrt(x+1)-sqrt(x).
Relevant Equations
f(x)=sqrt(x+1)-sqrt(x).
Hm I'm new to these concepts, and I want to make sure I am on the right track, would the relative condition number be:

k=(x/2)((1/sqrt(x+1))-(1/sqrt(x))(1/(sqrt(x+1)-sqrt(x))). Or would I have to solve the limit as x approaches 0?

Thank you.
 
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  • #2
I know condition number in numerical analysis but what is the concept or definition of "relative condition number" you say?
 
  • #3
ver_mathstats said:
Homework Statement:: Find the relative condition number for f(x)=sqrt(x+1)-sqrt(x).
Relevant Equations:: f(x)=sqrt(x+1)-sqrt(x).

Hm I'm new to these concepts, and I want to make sure I am on the right track, would the relative condition number be:

k=(x/2)((1/sqrt(x+1))-(1/sqrt(x))(1/(sqrt(x+1)-sqrt(x))). Or would I have to solve the limit as x approaches 0?

Thank you.
  1. I'm reasonably sure your equation above is written correctly, but it's really hard to parse.
  2. I'm not familiar with the term "relative condition number," but this wikipedia article (https://en.wikipedia.org/wiki/Condition_number) provides a definition. The section titled "Several variables" defines the term "relative condition number."
  3. From the above definition, the limit is on ##\delta x##, not x.
 
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FAQ: Finding A Relative Condition Number

1. What is a relative condition number?

A relative condition number is a measure of how sensitive a function or calculation is to small changes in the input. It is a way to quantify the stability or robustness of a calculation.

2. How is the relative condition number calculated?

The relative condition number is typically calculated by taking the ratio of the change in the output to the change in the input. This is usually represented as a percentage or decimal value.

3. Why is it important to find the relative condition number?

Knowing the relative condition number can help a scientist determine the accuracy and reliability of their calculations. It can also help identify potential sources of error and improve the overall quality of the results.

4. How can the relative condition number be used in scientific research?

The relative condition number can be used to compare different methods or algorithms for solving a problem. It can also be used to evaluate the effects of rounding errors or other sources of imprecision on the results of a calculation.

5. Are there any limitations to using the relative condition number?

While the relative condition number is a useful tool, it does have some limitations. It may not accurately reflect the stability of a calculation in all cases, and it may not be a good indicator of overall numerical accuracy.

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