- #1

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Consider '#' as lamda.

How to find roots(eigen values) of characteristic equation |A-#I| = 0.

I know how to find it it using numerical methods.

But can anyone plz show me how to procced for degree 3 equations.

thanks and regards.

- Thread starter zeroxff0000ff
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- #1

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Consider '#' as lamda.

How to find roots(eigen values) of characteristic equation |A-#I| = 0.

I know how to find it it using numerical methods.

But can anyone plz show me how to procced for degree 3 equations.

thanks and regards.

- #2

HallsofIvy

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http://www.math.vanderbilt.edu/~schectex/courses/cubic/

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just now i found some methods like factor and remainder theorem from the following link :

http://www.themathpage.com/aprecalc/factor-theorem.htm

can you plz tell me advantage and disadvantage of using factor and reminder theorem.

- #4

Office_Shredder

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You can use the integer root theorem (on the website you posted) to figure out which integers are worth guessing. The advantage is that most problems will have a root that you can find in this way. The disadvantage is that if the polynomial doesn't have an integer root, you can't find any roots using this method. But it doesn't take a lot of time to try, so usually this is the best way to start.

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mathwonk

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HallsofIvy

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And in particular, if f(a)= 0, the remainder is 0 so x-a is a factor of f(x).

It seems very strange to me that a person would be working with eigenvalues while not knowing how to solve polynomial equations by factoring!

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