Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2002
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2002

[Date Index] [Thread Index] [Author Index]

Search the Archive

Solving equations / real valued variables and parameters

  • To: mathgroup at smc.vnet.net
  • Subject: [mg33985] Solving equations / real valued variables and parameters
  • From: hannes.egli at uni-greifswald.de (Hannes Egli)
  • Date: Thu, 25 Apr 2002 03:00:07 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

Hi

I have got two questions.

(1)

If I try to solve the following equation for "m".
 
Solve[a/(a+b+n)-(a+b+n)*((a/(a+b+n))^a)*(((b+n)/(a+b+n))^(b+n))*m^(a+b+n-1)
= = 0, m]
 
I receive the error message "The equations appear to involve the
variables to be solved for in an essentially non-algebraic way".

However, if I set n=0, 

Solve[a/(a+b)-(a+b)*((a/(a+b))^a)*((b/(a+b))^b)*m^(a+b-1) = = 0, m]

Mathematica gives me a solution for "m".

m -> ((((a/(a+b))^a)*((b/(a+b))^b)*(a+b)^2)/a)^(1/(1-a-b))

I do not understand, why Mathematica does not give me a solution for
the first equation, since both equations look very similar.


(2)

My second question concerns real valued variables/parameters. Is there
a possibility to tell Mathematica (at the beginning of a notebook file
or within a function) that some variables and/or parameters are real
valued?


Thanks for your answers

Hannes


  • Prev by Date: Re: HoldForm Obscurities
  • Next by Date: a complex function appears in a real integration
  • Previous by thread: RE: Definite Integrals & Hidden Cells
  • Next by thread: a complex function appears in a real integration