Formula_15412

\[\left|\begin{array}{ccc}c_{11}-a_{11} k^{2} \ldots & c_{1 n}-a_{1 n} k^{2} \\\ldots & \ldots \\c_{n 1}-a_{n 1} k^{2} & \ldots & c_{n n}-a_{n n} k^{2}\end{array}\right|=0\]