In general solve cannot solve expressions which contain sqrt(foo(x)). to_poly_solve helps:
(%i1) load(topoly_solver)$
(%i2) to_poly_solve(2*x=sqrt(x^2+3),x);
(%o2) [[x = 1]]
Volker van Nek
Am 11 May 2008 um 9:16 hat Ronald Modesitt geschrieben:
>
> I don?t understand the following results from Solve.
> (%i4) y=2*x;
> (%o4) y=2*x
> (%i5) y=sqrt(x^2+3);
> (%o5) y=sqrt(x^2+3)
> (%i6) solve([%o4,%o5],[x,y]);
>
> (%i6) solve([%o4,%o5],[x,y]);`
> algsys' cannot solve - system too complicated.
> -- an error. To debug this try debugmode(true);
>
> The manual solution provides x=+/- 1. A quick look at the plot shows that x=-1 is not valid. Why
> does solve have a problem?
>
> Thanks
>
> Ron
>
>