Re: Self-teaching snag

*To*: mathgroup at smc.vnet.net*Subject*: [mg74599] Re: Self-teaching snag*From*: Peter Breitfeld <phbrf at t-online.de>*Date*: Tue, 27 Mar 2007 04:09:31 -0500 (EST)*References*: <eu7re0$b6p$1@smc.vnet.net>

Todd Allen schrieb: [*** snipp ***] > > charge[0]=1.0 (* 100% *); > charge[day_]:=(charge[day-1]-(0.05*charge[day-1])); > charge[20] [*** snipp ***] Allen, your function is a recursively defined one. Problems like this can be solved using RSolve: lsg=RSolve[{charge[t]==charge[t-1]-0.05charge[t-1], charge[0]==1},charge[t],t] charge[t_]=charge[t]/.lsg[[1]] gives the explicit term 0.95^t Gruss Peter -- ==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-== Peter Breitfeld, Bad Saulgau, Germany -- http://www.pBreitfeld.de