reduced functionality of Solve
- To: mathgroup at smc.vnet.net
- Subject: [mg44222] reduced functionality of Solve
- From: Andrew Collier <colliera at nu.ac.za>
- Date: Wed, 29 Oct 2003 03:34:05 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
hello, this may be a naive idea but i expected the functionality of software to improve with later releases. this, in my opinion, does not seem to be the case from mathematica 4.1 to 5.0... or maybe i am just missing something. in a script i have the following bit of code: ------------------------------------------------------------------------- F[W_, y_] := Exp[-W(Cos[y]^2/Tp + Sin[y]^2/Tn)] Tn = 3000; Tp = 2000; Solve[{D[F[W, y], y] Tan[y] == 2 F[W, y], W == 1000 Sec[y] ^ 2}, {W, y}]; N[%] // TableForm ------------------------------------------------------------------------- now, with mathematica 4.1 this gives: ------------------------------------------------------------------------- InverseFunction::ifun: Inverse functions are being used. Values may be lost for multivalued inverses. Solve::ifun: Inverse functions are being used by Solve, so some solutions may not be found. In[5]:= Out[5]//TableForm= W -> 7000. y -> -1.95839 W -> 7000. y -> 1.95839 W -> 7000. y -> -1.1832 W -> 7000. y -> 1.1832 ------------------------------------------------------------------------- which is useful and the kind of result i am after. however, after upgrading to mathematica 5.0 the same bit of code gives: ------------------------------------------------------------------------- Solve::tdep: The equations appear to involve the variables to be solved for in an essentially non-algebraic way. In[5]:= ------------------------------------------------------------------------- now i read in the manual that Solve "deals primarily with linear and polynomial equations", but i would expect that if i got a useful answer with 4.1 i should get the same (or better!) with 5.0. is there some way of getting the old behaviour with the newer version of mathematica? many thanks and best regards, andrew collier. -- Andrew B. Collier Antarctic Research Fellow tel: +27 31 2601157 Space Physics Research Institute fax: +27 31 2616550 University of Natal, Durban, 4041, South Africa
- Follow-Ups:
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- From: Andrzej Kozlowski <akoz@mimuw.edu.pl>
- Re: reduced functionality of Solve