If $$A$$ is square symmetric real valued matrix of dimension $$2n$$, then the eigen values of $$A$$ are

The eigen values of the matrix $$M$$ given are $$15, 3, $$ and $$0.$$
$$M = \left[ {\matrix{ 8 & { - 6} & 2 \cr { - 6} & 7 & { - 4} \cr 2 & { - 4} & 3 \cr } } \right],$$ the value of the determinant of a matrix is

For the following matrix $$\left[ {\matrix{ 1 & { - 1} \cr 2 & 3 \cr } } \right]$$ the number of positive characteristic roots is

Given matrix $$L = \left[ {\matrix{ 2 & 1 \cr 3 & 2 \cr 4 & 5 \cr } } \right]\,\,$$ and $$M = \left[ {\matrix{ 3 & 2 \cr 0 & 1 \cr } } \right]$$
then $$L \times M$$ is