Suppose I have a p-component non-null column vector $\mathbf{a}$. Then what will be the eigen roots of the matrix $\mathbf{A} = \mathbf{aa'}$.

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  • $\begingroup$ what do you mean by eigen roots? $\endgroup$
    – user251257
    Jul 13, 2015 at 10:07

1 Answer 1


Since, $A = a a' $ We get,

$$A^2 = (a'a) A$$ Using this we can get the characteristic equation as:

$$ \lambda^p = (a'a) \lambda^{p-1}$$

Now solve the equation and you will get your answer.


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