Re: 'Solve' problem

maxima-bounces <at> math.utexas.edu wrote on 07/01/2011 11:16:42 AM:

> eq1:exp(-3*x)=9/17;
> soln:-1/3*ln(9/17)-2/3*%i*%pi*5;
> subst(soln,x,eq1);
> 
> This returns exp(ln(9/17)) = 9/17
> 
> for any integer z, x=-1/3*ln(9/17)-2/3*%i*%pi*z is a solution.
> 
> True?

Try this:

 (%i33) load(to_poly_solver)$

 (%i34) eq : exp(-3*x)=9/17;
 (%o34) %e^(-3*x)=9/17

 (%i35) %solve(eq,x);
 (%o35) %union([x=(2*%i*%pi*%z15+log(17/9))/3])

 (%i36) subst(first(%), eq),rectform;
 (%o36) 9/17=9/17

Here %z15 is an arbitrary integer--also, the code automatically declares 
%z15 to
be an integer:

 (%i37) facts(%z15);
 (%o37) [kind(%z15,integer)]

--Barton