Representation of the characteristic polynomial of a two-channel system by a norm of an algebraic function

A new representation of the characteristic polynomial of a two-channel system by a norm of an algebraic function is proposed. The norm is obtained from the solution of the second-order algebraic equation for the transfer matrix. The discriminant of the algebraic equation determines the type of solution: real, complex, irreducible, and with a radical. For each solution type, an applied example of a two-channel system in aviation and power engineering is presented.