Newbie: problem solving basic equations



Hi - I intended to write logexpand:super , which does solve the problem.
Generally speaking, with most computer algebra systems you have to give the
program some assistance at some stage in the calculation.  I think that this
is the point that Dr. Fateman was trying to get across; you have to be
willing to use things like expand and factor.

> -----Original Message-----
> From:	Daniel Lemire [SMTP:lemire at ondelette]
> Sent:	Monday, October 01, 2001 7:55 PM
> To:	David Holmgren; maxima@www.math.utexas.edu
> Subject:	Re: [Maxima] Newbie: problem solving basic equations
> 
> I'm not sure what logexpand does, but clearly, we are nowhere near 
> finding a solution to log(a*x)=C*log(b*x) for x!!!
> 
> See what I get...
> 
> 
> (C1) logexpand:true;
> 
> 
> (D1) 					  TRUE
> (C2) solve(log(a*x)=C*log(b*x),x);
> 
> 
> 					     LOG(a x)
> (D2) 				 [LOG(b x) = --------]
> 						C
> 
> 
> David Holmgren wrote:
> 
> > Hi - Try this for a start (on the expression with the logs):
> >   logexpand:true;
> >   solve(log(a*x)-C*log(b*x),x);
> > 
> >  I have not yet found anything similar for exponentials...
> > 
> >  Dave Holmgren
> > 
> > Dr. David E. Holmgren,
> > Imaging Scientist,
> > SMART Technologies, Inc.
> > Calgary, AB, Canada
> > http://www.smarttech.com
> > [403]-235-1452, ext. 251
> > DavidHolmgren@smarttech.com
> > 
> > 
> > 
> >>-----Original Message-----
> >>From:	Daniel Lemire [SMTP:lemire at ondelette]
> >>Sent:	Monday, October 01, 2001 5:12 PM
> >>To:	maxima@www.ma.utexas.edu
> >>Subject:	[Maxima] Newbie: problem solving basic equations
> >>
> >>Good day,
> >>
> >>I think the "solve" function is broken. I just installed Maxima and 
> >>tried solving a few elementary equations. In all cases but the very, 
> >>very elementary ones, Maxima is no good, it seems. (See below.)
> >>
> >>
> >>What am I missing? Surely, Maxima can do this?
> >>
> >>[lemire@romeo lemire]$ maxima
> >>GCL (GNU Common Lisp)  Version(2.4.0) Wed May  9 12:02:00 CDT 2001
> >>Licensed under GNU Library General Public License
> >>Contains Enhancements by W. Schelter
> >>Maxima 5.6 Wed May 9 12:01:49 CDT 2001 (with enhancements by W.
> Schelter).
> >>Licensed under the GNU Public License (see file COPYING)
> >>(C1) solve(exp(a*x)= C*exp(b*x),x);
> >>
> >>                                            a x
> >>                                    b x   %E
> >>(D1)                            [%E    = -----]
> >>                                            C
> >>(C2) solve(log(a*x)=C*log(b*x),x);
> >>
> >>                                          LOG(a x)
> >>(D2)                         [LOG(b x) = --------]
> >>                                             C
> >>(C3) solve(a^x=b^x,x);
> >>
> >>                                      x    x
> >>(D3)                               [b  = a ]
> >>(C4) solve(m*x+b=y,x);
> >>
> >>                                        y - b
> >>(D4)                              [x = -----]
> >>                                          m
> >>(C5)
> >>-- 
> >>Daniel Lemire, Ph.D.
> >>
> >>http://www.ondelette.com/
> >>
> >>
> >>_______________________________________________
> >>Maxima mailing list
> >>Maxima@www.math.utexas.edu
> >>http://www.math.utexas.edu/mailman/listinfo/maxima
> >>
> > 
> 
> 
> 
> -- 
> Daniel Lemire, Ph.D.
> 
> http://www.ondelette.com/
>