On Thu, Sep 2, 2010 at 10:11, Richard Fateman <fateman at cs.berkeley.edu>wrote
>
> try ev(eq,exponentialize);
> solve(%,x);
>
> The solutions look like
>
> [x=-%i*log(%i*((%i*y0)/(%i*y0+x0)-x0/(%i*y0+x0))^(1/4)),
> x=-%i*log(-((%i*y0)/(%i*y0+x0)-x0/(%i*y0+x0))^(1/4)),
> x=-%i*log(-%i*((%i*y0)/(%i*y0+x0)-x0/(%i*y0+x0))^(1/4)),
> x=-(%i*log((%i*y0)/(%i*y0+x0)-x0/(%i*y0+x0)))/4]
>
> which may not be what you had in mind.
>
... but rectform then ratsimp gets you the solutions in terms of atan2 --
though atan2 would really benefit from simplifying things of the form
atan2(x/POS,y/POS) => atan2(x,y).
-s