On 11/25/2012 03:57 PM, Norman Werner wrote:
> Hello,
>
> I am using maxima as a common-lisp library for a pet-project of mine.
> However I stumbled upon a problem when using solve.
>
> I try to solve an equation or a set of equation and I do introduce
> known variables by
> adding an appropriate equation to the set. Eg:
>
> solve([1=a*x,a=1],[a,x]);
> -> [[a = 1, x = 1]]
>
> Which works fine! If the equation however contains functions like exp,
> log, or sin solve won't find any solutions:
>
> solve([1=a*sin(x),a=1],[a,x]);
> -> []
> solve([1=a*log(x),a=1],[a,x]);
> -> []
> (%i125) solve([1=a*exp(x),a=1],[a,x]);
> -> []
>
> Obviously the solutions to those problems are not as obvious as they
> seem. Could someone clarify this behaviour? What's the correct way to
> solve such problems with maxima?
(%i3) load(to_poly_solver)$
(%i4) %solve([1=a*sin(x),a=1],[a,x]);
(%o4) %union([a = 1,x = 2*%pi*%z7+%pi/2])
(%i5) %solve([1=a*log(x),a=1],[a,x]);
(%o5) %union([a = 1,x = %e])
(%i6) %solve([1=a*exp(x),a=1],[a,x]);
(%o6) %union([a = 1,x = 2*%i*%pi*%z23])
%z7 and %z23 mean any integer.
Regards,
Jaime