'Solve' problem



-----maxima-bounces at math.utexas.edu wrote: -----

>Thank?you?for?your?reply.?I?saw?the?long?list?of?x's?when?I?tried
>solve(exp(-20*x)=9/17,x).
>
>Myy?question?now?is?:?Is?there?a?way?to?tell
>solve?that?I?only?the?real?solution?of?this?equation?

No, but this might help get you the real solution:

(%i1) load(to_poly_solver)$
Loading maxima-grobner $Revision: 1.6 $ $Date: 2009/06/02 07:49:49 $

Here, %z5 is an arbitrary integer

 (%i2) %solve(exp(-20000*x)=9/17,x);
 (%o2) %union([x=(2*%i*%pi*%z5+log(17/9))/20000])

To shift the counter on %z5 to zero, use nicedummies

 (%i3) nicedummies(%);
 (%o3) %union([x=(2*%i*%pi*%z0+log(17/9))/20000])

There is no Maxima tool for selecting the real solution; for that, you'll
need to do some carbon-based (brain) computation (set %z5 to zero) 

--Barton (author of to_poly_solver)