Finding roots of sextic in radicals + Bug?

Stavros Macrakis escribi?:
> Nice solution!  Maxima actually lets you do this even more simply:
> 
>     p: x^6+3*x^5+6*x^4+3*x^3+9*x+9;
>     p2: factor(p,q^3-2)$
>     solve(subst(q=2^(1/3),p2),x);
> 
>              -s

I've never seen factor used like that. The manual doesn't explain what 
that call should do!
(Relevant manual entry: 
http://maxima.sourceforge.net/docs/manual/en/maxima_12.html#IDX404 )

I was trying to figure out what that did, but I get this error:

(%i1) factor(x^3+x*2, q^2-1);
Maxima encountered a Lisp error: Error in PROGN [or a callee]: Caught 
fatal error [memory may be damaged]Automatically continuing.To reenable 
the Lisp debugger set *debugger-hook* to nil.(%i2)

Is this a bug?

What does "factor(expr, expr)" do?


Thanks,
Ismael