Re: Exponential Equations

*To*: mathgroup at smc.vnet.net*Subject*: [mg28801] Re: Exponential Equations*From*: "Paul Lutus" <nospam at nosite.com>*Date*: Mon, 14 May 2001 01:32:54 -0400 (EDT)*References*: <9dlcea$o31@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

"Phil Larson" <PLarson at bju.edu> wrote in message news:9dlcea$o31 at smc.vnet.net... > Why can't Mathematica find x = -5/2 when executing the following? Is > there a package I should load? It seems so simple. > > Solve[3^(2 x)==(1/9)^(x + 5),x] What do you mean? Solve[] solves it as written. Solve[] is not meant to find a particular numerical root of an equation, it is designed to find all symbolic solutions if it can. For this equation, it can and does. If you want just a single numerical root, use FindRoot[]. -- Paul Lutus www.arachnoid.com