I am trying to prove that the following matrix is positive semidefinite: A = [2 1 2; 1 1 1; 2 1 2]. I found that the eigenvalues are 0, 0, and 5. After finding the row echelon form, the pivots are greater than 0. So, this should mean that the matrix is positive semidefinite. But when I try to test the principal submatrices, some of them are less than 0. That means that the matrix is not positive semidefinite. Am I doing this wrong? Can you prove this is a positive semidefinte matrix with the use of the "No principal submatrices have negative determinants" rule?
I am trying to prove that the following matrix is positive semidefinite: A = [2 1 2; 1 1 1; 2 1 2]. I found that the eigenvalues are 0, 0, and 5. After finding the row echelon form, the pivots are greater than 0. So, this should mean that the matrix is positive semidefinite. But when I try to test the principal submatrices, some of them are less than 0. That means that the matrix is not positive semidefinite. Am I doing this wrong? Can you prove this is a positive semidefinte matrix with the use of the "No principal submatrices have negative determinants" rule?
Algebra and Trigonometry (6th Edition)
6th Edition
ISBN:9780134463216
Author:Robert F. Blitzer
Publisher:Robert F. Blitzer
ChapterP: Prerequisites: Fundamental Concepts Of Algebra
Section: Chapter Questions
Problem 1MCCP: In Exercises 1-25, simplify the given expression or perform the indicated operation (and simplify,...
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I am trying to prove that the following matrix is positive semidefinite: A = [2 1 2; 1 1 1; 2 1 2]. I found that the eigenvalues are 0, 0, and 5. After finding the row echelon form, the pivots are greater than 0. So, this should mean that the matrix is positive semidefinite. But when I try to test the principal submatrices, some of them are less than 0. That means that the matrix is not positive semidefinite.
Am I doing this wrong? Can you prove this is a positive semidefinte matrix with the use of the "No principal submatrices have negative determinants" rule?
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