The calculation for characteristic multiplier of Hill's equation in case q(t)Â <Â 0

We have given the calculation for characteristic multiplier of Hill's equation x″ + q(t)x = 0 in case q(t) > 0 in the work of Jinlin Shi et al. [Appl. Math. Comput., in press (AMC8559)]. In this paper, we consider the calculation for characteristic multiplier in case q(t) < 0.