Apparently, this user prefers to keep an air of mystery about them.
7 The determinant of block triangular matrix as product of determinants of diagonal blocks dec 27 '12
4 Find characteristic polynomial of $\,A^2$ if the characteristic polynomial of $\,A$ is $\,t^4 -t$ nov 20 '13
3 Show that $rank(A)+rank(B) \leq n$, when $A,B$ are $2$ matrices of size $n \times n$, and $AB=0$ dec 1 '12
2 prove that if $\lambda$ is an eigenvalue of T then $\bar\lambda$ is eigenvalue of $T^*$ dec 19 '13