Automatic plotting of characteristic curves and analog solution of algebraic equations

For the characteristic equation an sn+an¿1 sn¿1+¿ +a2 s2+¿s+¿=0 the relations between the coefficients ¿ and ¿ and the values ¿¿n and ¿n2 are derived. The computer based on these relations may be used for plotting the characteristic curves used in the graphical analysis and synthesis of linear feedback control systems, for determination of roots of algebraic equations with real coefficients, and for plotting of root-locus for an arbitrary parameter.