Re: System of NonLinear Inequalities

*To*: mathgroup at smc.vnet.net*Subject*: [mg48589] Re: [mg48511] System of NonLinear Inequalities*From*: "maurizio lisciandra" <lisciandra at hotmail.com>*Date*: Sat, 5 Jun 2004 19:58:09 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Thanks Andrzej, I did wrote with the correct syntax when I put the system in Mathematica. I did find a solution though. I just run a loop with do and substitute for x, a, and F, and I found out that the solution is empty. At the beginning I thought that a Mathematica could do something like this, but then I realised that I was asking too much. I find this software extraordinary though. Thank you anyway for your answer. Maurizio. >From: Andrzej Kozlowski <akoz at mimuw.edu.pl> To: mathgroup at smc.vnet.net >To: "maurizio lisciandra" <lisciandra at hotmail.com> >CC: mathgroup at smc.vnet.net >Subject: [mg48589] Re: [mg48511] System of NonLinear Inequalities >Date: Fri, 4 Jun 2004 23:10:01 +0900 > >First of all, your inequalities are not written using Mathematica syntax >(you can't use square brackets in this way). But looking at them I see it >does not matter whether you use proper syntax or not: no computer program >will ever solve a system of inequalites involving someting like x^(2/(2 - >x)). Your only chance is a human brain and some fantastic stroke of luck. >Sorry for being so unhelpful. > >Andrzej > >On 4 Jun 2004, at 17:49, maurizio lisciandra wrote: > >>Dear Friends, >> >>I tried to solve the following system of nonlinear inequalities with >>Mathematica 5.0: >> >>F < (1/2)*[a^(x/(2 - x))]*[x^(2/(2 - x))] && >>(2*a*B)^(x/2) + F - B > (2*a*F)^(x/2) && >>F > B > 0 && >>0 <= a <= 1 && >>0 < x < 2. >> >>I tried with Reduce, SolveInequality, SemiAlgebraicComponent, >>FindInstance, >>but all these function do not solve it. I tried to substitute x for some >>fixed value, but again I cannot solve it. The only value that I can >>substitute for x is 1, and in this case the solution is an empty space. I >>may be happy if I find a value that solves the system, although I really >>need for which inetervals in the variable this system is not an empty >>space. >> >>Hope some nice Mathematica expert can help me. >> >>Cheers, >> >>Maurizio Lisciandra >>Trinity College >>Cambridge (UK) >> >>_________________________________________________________________ >>Ricerche online più semplici e veloci con MSN Toolbar! >>http://toolbar.msn.it/ >> >> > _________________________________________________________________ Personalizza MSN Messenger con sfondi e fotografie! http://www.ilovemessenger.msn.it/