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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