Le vendredi 17 octobre 2014 16:37:55 UTC+2, vdelecroix a écrit :
>
> 2014-10-17 10:09 UTC, Emmanuel Charpentier <emanuel.c...@gmail.com
> <javascript:>>:
> > Ahem !
> >
> > On one machine :
> >
> > sage: sage.version.version
> > '6.4.beta4'
> > sage: var("w,t")
> > (w, t)
> > sage: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w)
> > [w == 1/2*t*sqrt(4*w + 2)]
>
> This solution is implicit. This is the problem.
>
Indeed. But one can get solutions for an equation close to this implicit
solution :
sage: E1=-(1/2*sqrt((4*w+1)+1))*t+w==0
sage: S1=E1.solve(w)
sage: S1
[w == 1/2*t*sqrt(4*w + 2)]
sage: S2=(S1[0]^2).solve(w)
sage: S2
[w == 1/2*t^2 - 1/2*sqrt(t^2 + 2)*t, w == 1/2*t^2 + 1/2*sqrt(t^2 + 2)*t]
A bit of numerics (plotting for t \in [-1,1]) shows that [S2[0] isn't
acceptable but that S2[1] might be. I didn't (yet) succeed in proving this.
Any idea ?
--
Emmanuel Charpentier
--
You received this message because you are subscribed to the Google Groups
"sage-support" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to sage-support+unsubscr...@googlegroups.com.
To post to this group, send email to sage-support@googlegroups.com.
Visit this group at http://groups.google.com/group/sage-support.
For more options, visit https://groups.google.com/d/optout.
