Re: Bugs with transcendental functions?
- To: mathgroup at christensen.cybernetics.net
- Subject: [mg1813] Re: Bugs with transcendental functions?
- From: fateman at peoplesparc.cs.berkeley.edu (Richard J Fateman)
- Date: Mon, 31 Jul 1995 23:09:40 -0400
- Organization: University of California, Berkeley
In article <DCBwtr.4z1 at wri.com>, Bill Rowe <wjrowe at ccgate.HAC.COM> wrote:
...
>|2. Input:=
>| Solve[a (-Log[x + a z]+ Log[ w + a z])/qq== y, x]
>|Solve::tdep:
>| The equations appear to involve transcendental
>| functions of the variables in an essentially
>| non-algebraic way.
>|Output:=
>| a (Log[w + a z] - Log[x + a z])
>|Solve[------------------------------- == y, x]
>| qq
>I am sure it is not a bug related to your version of MMA since I get the
>same result using MMA version 2.2.1 on a Macintosh.
.....
>Basically the behavior you describe is not a bug but a result of the
>design of the Solve function.
No, its a bug. Here's a newer version of Mathematica. (version 2.2 on
HP 9000).
In[1]:= Solve[a (-Log[x + a z]+ Log[ w + a z])/qq== y, x]
(-(qq y) + a Log[w + a z])/a
Out[1]= {{x -> E - a z}}
This bug was fixed some time ago, I thought. It would, in any case,
be a strange interpretation of symbolic constants like a or qq
to think that they may all depend on the unknown(s) you are solving
for (here, x). You could hardly solve any equation under those
assumptions.
RJF
--
Richard J. Fateman
fateman at cs.berkeley.edu 510 642-1879