Re: RSolve and complex solutions

*To*: mathgroup at smc.vnet.net*Subject*: [mg54719] Re: RSolve and complex solutions*From*: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>*Date*: Mon, 28 Feb 2005 03:27:04 -0500 (EST)*Organization*: Uni Leipzig*References*: <cvrq1t$p28$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi, a) RSolve work pure symbolical, there can't be rounding errors b) RSolve[] will Solve[] at least a system of equations and this can produce complex solutions even for real input. Regards Jens "Skirmantas" <skirmantas.janusonis at yale.edu> schrieb im Newsbeitrag news:cvrq1t$p28$1 at smc.vnet.net... > It may be a basic math question, but it would be helpful if somebody > could briefly comment on it. If I have a system of recursion equations > with real coefficients and solve it numerically step-by-step, all my > solutions at all time steps are (obviously) real. If, however, I use > RSolve to get the general formulas for these solutions, some of them > become complex numbers. My understanding is the imaginary parts of > these numbers are due to rounding errors and the actual solutions are > only the real parts. Am I right? >