2-28. The characteristic equation of a series RLC circuit shown in Fig. P2.28 is given as R 1 2 s+ = 0. L LC a. If R = 7, L = 1 H, and C = 0.1 F, solve the quadratic equation (2.69) for the values of s (called the eigenvalues of the system) using the methods of completing the square and the quadratic formula. b. Repeat part (a) if R = 10 S, L = 1 H, and C = F. 25 + Vc (0) C i(t) t = 0 R Figure P2.28 Series RLC circuit for problem P2-28. DLA iscuit shown in Fig. P2.29 is given as 00000 L (2.70)