#Basic linear algebra project

22 messages · Page 1 of 1 (latest)

rare frigateBOT
paper schooner
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You assessment sounds right to me, though I don't remember linear algebra as well as other subjects.

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but it finds the characteristic polynomialhttps://www.symbolab.com/solver/matrix-diagonalization-calculator/det%5Cbegin%7Bpmatrix%7D0-x%261%261.9%261.7%260%5C%5C%20%20%20%20%20%20.61%260-x%260%260%260%5C%5C%20%20%20%20%20%200%26.33%260-x%260%260%5C%5C%20%20%20%20%20%200%260%26.21%260-x%260%5C%5C%20%20%20%20%20%200%260%260%26.13%26.08-x%5Cend%7Bpmatrix%7D?or=input

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which wolfram says has 5 distinct rootshttps://www.wolframalpha.com/input?i=0%3D+-x%5E5+%2B.08x%5E4+%2B0.61x%5E3+%2B+0.33367x%5E2%2B+0.0412665x+-0.005749128

ruby oxide
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ah ez

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well someone already mentioned it

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but yeah you diagonalise it by finding its eigenvalues and eigenvectors and then u get a PDP^-1 decomposition

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also known as the eigendecomposition

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then your D matrix contains only diagonals. a Diagonal matrix to nth power is just its individual elements to the 10th power, making it easier

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then you dot product the whole thing back to get the final matrix

tired ingot
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we're supposed to do it by hand though... and finding eigenvalues involves finding determinants and the determinant of a 5x5 matrix is not something i'm willing to do

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i've used websites and numpy and stuff and even went through papers on leslie matrices (and this doesn't even follow the proper form of one) and i literally can't find anything. this whole course has been incredibly easy though so i'm very confused if i'm just overlooking something really obvious

ruby oxide
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then u can just multiply the diagonals for the deteriminants

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but i think in that case, since u only have one non diagonal row, u can find a shortcut to solve eigenvalues and eigenvectors too

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sadly i have now forgotten what that trick was

tired ingot
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sorry am i going crazy or something? if i swap row 1 and 2, then the third row still would have a value on the second column which is below the diagonal so it's not an upper triangular matrix?

ruby oxide
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yeah sorry my bad

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i have forgotten all the tricks but i am sure there was a trick for eigen vectors for such situations

tired ingot
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so far in this course the only things they've only covered very basic matrix operations... nothing even close to diagonalisation and eigenvectors and stuff. i've done linear algebra quite extensively before this so i don't mind using something more advanced but i'm confused what they expect me to do