Recent content by elimax

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    Undergrad Is xTAx always non-zero for a real, symmetric, nonsingular matrix A?

    Basic question, I think, but I'm not sure. It is a step in a demonstration, so it would be nice if it were true. True or false? Why? If A is a real, symmetric, nonsingular matrix, then xTAx≠0 for x≠0.
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    Find eingenvalues and eigenvectors of an order n matrix

    Homework Statement Being T\in L(\mathbb{R}^n) a linear operador defined by T(x_1, ... ,x_n )=(x_1+...+x_n,...,x_1+...+x_n ), find all eigenvalues and eigenvectors of T. Homework Equations det(T-\lambda I)=0, Ax=\lambda x The Attempt at a Solution By checking n=1,2,3,4 I guess the...