Re: Replace in recursive equations

*To*: mathgroup at smc.vnet.net*Subject*: [mg54406] Re: [mg54371] Replace in recursive equations*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Sun, 20 Feb 2005 00:08:08 -0500 (EST)*Reply-to*: hanlonr at cox.net*Sender*: owner-wri-mathgroup at wolfram.com

eqn=f[n+1]==a*f[n]; eqn /. f[n__] :> ff[n]+Q Q + ff[n + 1] == a*(Q + ff[n]) Needs["DiscreteMath`RSolve`"]; RSolve[{f[n+1]==a*f[n],f[0]==c},f[n],n] {{f[n] -> a^n*c}} Bob Hanlon > > From: skirmantas.janusonis at yale.edu (Skirmantas) To: mathgroup at smc.vnet.net > Date: 2005/02/19 Sat AM 02:32:32 EST > To: mathgroup at smc.vnet.net > Subject: [mg54406] [mg54371] Replace in recursive equations > > The last sentence of my previous message about Inverse got somehow > scrambled. I meant "I have to re-input the output to get the result." > > One more quick question. Suppose I have a recursive equation F[n+1]==a > F[n]. I want to replace F[n]->FF[n]+Q for _all_ n's. Q is a constant. > What is the best way to do it? The left side should become FF[n+1]+Q > and the right a(FF[n]+Q). Any help would be appreciated. > >