# Finding roots of a matrix equation

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kimi on 17 Jul 2020
Commented: kimi on 24 Jul 2020
Hello,
I'm having trouble getting roots for this matrix. The example has to do with finding the natural frequency and mode shapes of a a simple rigid rotor system on anisotropic flexible supports. I have the formula, answer, and polynomial from the matrix equation just struggling to find the roots. Please help.
The question is example 3.6.1(a) finding roots s1-8.
I believe im solving for q and q` but im not sure how to put this in matlab. Or maybe us

Devineni Aslesha on 20 Jul 2020
Refer the roots documentation from the given link

kimi on 24 Jul 2020
My values are still way off. I'm going to try another similar problem.
>> s = eig(B,A)
s =
-7.00429151535041e-15 + 90.3168809902389i
-7.00429151535041e-15 - 90.3168809902389i
1.14751809725569e-18 + 4.33505975508429i
1.14751809725569e-18 - 4.33505975508429i
0 + 4.32548302517613i
0 - 4.32548302517613i
9.33170852334867e-18 + 0.546468920033129i
9.33170852334867e-18 - 0.546468920033129i
Walter Roberson on 24 Jul 2020
s = eig(B,A) but before it was eig(B, -A)
kimi on 24 Jul 2020
That was a mistake the values aren't that different