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I have the following matrix

\begin{bmatrix} 15.52 & 0.00 & -14.52 \\ -11.05 & 1.00 & 11.05 \\ -0.01 & 0.00 & 0.01 \end{bmatrix}

I am supposed to calculate the condition number as the ratio between its maximum and minimum eigenvalue. My result is 24116.0899 using $ k(A)=\Big\vert\frac{\lambda _{\max}(A)}{\lambda _{\min}(A)} \Big\vert$ But the official result is $5.86 \cdot 10^{4}$.

Can somebody help me?

Thank you

Ben Grossmann
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Felipe Ca
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    Are you sure you have the right values in the matrix? plugging into wolfram I get the same result as you. – JMoravitz Jul 22 '20 at 19:18
  • My result in wolframalpha is 46652.1 https://www.wolframalpha.com/input/?i=%7B%7B15.52%2C0%2C-14.52%7D%2C%7B-11.05%2C1%2C11.05%7D%2C%7B-0.01%2C0%2C0.01%7D%7D – user376343 Jul 22 '20 at 19:34
  • I can't find any interpretation of "condition number" that produces the "official result" that you refer to – Ben Grossmann Jul 22 '20 at 19:38
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    @Felipe Note that the quantity that is normally called "the condition number" is not the same thing as the ratio between the maximum and minimum eigenvalues; it is instead the ratio between the maximum and minimum singular values. – Ben Grossmann Jul 22 '20 at 19:39
  • @JMoravitz the values are correct, Thank you very much for your response, I will try to find out how that value was obtained – Felipe Ca Jul 22 '20 at 19:44
  • @BenGrossmann sorry, the "official result" is a result obtained in a research paper that I have been reading. The author of this paper calculate the condition number like the ratio between its maximum and minimum eigenvalue. So my problem is that my results are different. Thank you for your contribution – Felipe Ca Jul 22 '20 at 20:00
  • @FelipeCar Interesting. Is the paper publicly available? – Ben Grossmann Jul 22 '20 at 20:47

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