Re: reduced functionality of Solve

*To*: mathgroup at smc.vnet.net*Subject*: [mg44285] Re: reduced functionality of Solve*From*: Paul Abbott <paul at physics.uwa.edu.au>*Date*: Tue, 4 Nov 2003 03:23:58 -0500 (EST)*Organization*: The University of Western Australia*References*: <bnnusd$5vc$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

In article <bnnusd$5vc$1 at smc.vnet.net>, Andrew Collier <colliera at nu.ac.za> wrote: > 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. 5.0 is being more careful that 4.1. > 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 > ------------------------------------------------------------------------- Replace Solve with Reduce. Reduce gives the complete family of solutions, including arbitrary constants corresponding to the non-uniqueness of the solution. [However, I note tha FullSimplify in Mathematica 5.0 does not simplify 2 ArcTan[Sqrt[(1/3) (4 - Sqrt[7])]] to ArcTan[Sqrt[6]]] but it does verify that FullSimplify[Tan[2 ArcTan[Sqrt[(1/3) (4 - Sqrt[7])]]] - Sqrt[6]] returns 0.] 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