Maxima Solve question



Ronald Modesitt escribi?:
> 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?

Yet, doing:
(%i1) y = 2*x;
(%o1) y=2*x
(%i2) y=sqrt(x^2+3)
(%o2) y=sqrt(x^2+3)
(%i3) solve([%o1,%o2], [x,y]);
`algsys' cannot solve - system too complicated. -- an error.  To debug 
this try debugmode(true);

(%i4) solve([%o1,%o2^2], [x,y]);
(%o4) [[x=-1,y=-2],[x=1,y=2]]

Gets a solution. That's strange!


Ismael