Given four complex matrices $A$, $B$, $C$ and $D$ where $Ainmathbb{C}^{ntimes n}$ and $Dinmathbb{C}^{mtimes m}$ and let the matrix $left(begin{array}{cc} A & B C & D end{array} right)$ be a normal matrix and assume that $lambda$ is a given complex number that is not eigenvalue of matrix $A$. We present a method to calculate the distance norm (with respect to 2-norm) from $D$ to ...
