Arrangement of eigenvalues in a Diagonal matrix

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Eigenvalues in a diagonal matrix do not need to be arranged in increasing order; different arrangements yield valid diagonal matrices. The order of eigenvalues affects the corresponding diagonal matrix D, but multiple configurations can still diagonalize the same matrix A. There is no single correct ordering for eigenvalues, as different arrangements of eigenvectors can lead to different diagonal forms. The flexibility in ordering allows for various representations of the matrix. Thus, it is not necessary to adhere to a specific sequence when arranging eigenvalues.
coconut62
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Homework Statement



Is it necessary to arrange the eigenvalues in increasing value order?

As shown in the image attached, if I arrange my eigenvalues -2, -1, 1 diagonally, my D would be
2^8 , 1, 1 diagonally.

However if i arrange it as, say, -1, 1, -2, my D would be different.

Just want to make sure of it, thanks.
 

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coconut62 said:

Homework Statement



Is it necessary to arrange the eigenvalues in increasing value order?

As shown in the image attached, if I arrange my eigenvalues -2, -1, 1 diagonally, my D would be
2^8 , 1, 1 diagonally.

However if i arrange it as, say, -1, 1, -2, my D would be different.

Just want to make sure of it, thanks.

Good work. Yes, there is more than one matrix P that will diagonalize A. You can arrange the eigenvectors in P in a different order and get the eigenvalues in a different order along the diagonal. I don't think anyone order is more correct than another.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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