If and .
Because this is a symmetric matrix if the diagonal is zero consider the following.
.
But that can only happen if and only if .
Question:
A is an nxn symmetric matrix (A^t=A). if the all diagonal elements of the matrix Asquared =AA are zero, prove that the matrix A must be a zero matrix(all elements of matrix A are zero's.
been trying for days to figure out need help badly!!!