Re: Showing that ArcSinh[2]/ArcCsch[2] is 3?
- To: mathgroup at smc.vnet.net
- Subject: [mg73528] Re: [mg73499] Showing that ArcSinh[2]/ArcCsch[2] is 3?
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Wed, 21 Feb 2007 01:45:34 -0500 (EST)
- Reply-to: hanlonr at cox.net
expr=ArcSinh[2]/ArcCsch[2];
Rationalize[expr,10^-100]
3
Reduce[{ArcSinh[x]/ArcCsch[x]==3,x>0},x]
x == 2
Off[N::meprec];
expr==3//FullSimplify
True
On[N::meprec];
Bob Hanlon
---- "David W.Cantrell" <DWCantrell at sigmaxi.net> wrote:
> I hope I've just overlooked something very simple.
> I want to transform ArcSinh[2]/ArcCsch[2] to 3, using just "knowledge"
> already implemented in Mathematica. I tried FullSimplify first, and it
> doesn't help. I tried several other things. For example,
>
> TrigToExp[ArcSinh[2]/ArcCsch[2]] yields
>
> Log[2 + Sqrt[5]]/Log[1/2 + Sqrt[5]/2].
>
> But then how should we transform that to 3?
>
> David