Re: maximization question
- To: mathgroup at smc.vnet.net
- Subject: [mg42825] Re: maximization question
- From: Paul Abbott <paul at physics.uwa.edu.au>
- Date: Wed, 30 Jul 2003 19:30:10 -0400 (EDT)
- Organization: The University of Western Australia
- References: <bfo59o$cg5$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
In article <bfo59o$cg5$1 at smc.vnet.net>, "Tun Lin" <tunlin220 at hotmail.com> wrote: > I try to solve a maximization problem and get stuck at the first step. This > step is to maximize a function with four inequality constraints, which I > describe in the link following. I first solved the question by hand (the > results are also shown in the link), then tried mathematica. I kept getting > error messages as shown and the results are different. What is the problem? > > The question and command line is at: > > http://www.pbase.com/image/19486173/original Well, the given hand solution to the problem posted there is not correct (instead of using the approximate multiplier and power 0.5, I use the exact 1/2 instead)! This can be seen as follows: In[1]:= { (1/2)(Sqrt[qH] - tH) + (1/2)(Sqrt[qL] - tL), tL - bL qL >= 0, tH - bH qH >= 0, tL - bL qL >= tH - bL qH, tH - bH qH >= tL - bH qL, qL >= 0, qH >= 0, tL >= 0, tH >= 0} /. {bH -> 2, bL -> 20} /. {qL -> 1/16, qH -> 1/5776, tL -> 20/5776, tH -> 740/5776} Out[1]={5/76, False, True, False, True, True, True, True, True} Clearly tL is less than bL qL! Cheers, Paul -- Paul Abbott Phone: +61 8 9380 2734 School of Physics, M013 Fax: +61 8 9380 1014 The University of Western Australia (CRICOS Provider No 00126G) 35 Stirling Highway Crawley WA 6009 mailto:paul at physics.uwa.edu.au AUSTRALIA http://physics.uwa.edu.au/~paul