parameters problem in FindFit

*To*: mathgroup at smc.vnet.net*Subject*: [mg92855] parameters problem in FindFit*From*: gyzhou at 139.com*Date*: Wed, 15 Oct 2008 05:37:53 -0400 (EDT)

Hi, guys : I get a list like this : lis = {{12.5, 1.146}, {32, 1.145}, {50, 1.144}, {69, 1.1424}, {84.6, 1.139}} My aim is : FindFit[lis, a - (b x^2)/(c + x), {{a, 1.14}, {b, 0.0003}, {c, 300}}, x] As we can see, I want this list to be fitted using parameters a, b, c around 1.14, 0.0003, 300. However Mathematica gives { b, 10^8} and {c, 10^14} far from what I expect.I set "MaxIterations" to less times, but it doesn' t make sense. My friends didn't give the answer either, I am here for your advice. Thanks in advance.

**Follow-Ups**:**RE: parameters problem in FindFit***From:*"Richard Hofler" <rhofler@bus.ucf.edu>