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Re: Showing that ArcSinh[2]/ArcCsch[2] is 3?

• To: mathgroup at smc.vnet.net
• Subject: [mg73518] Re: [mg73499] Showing that ArcSinh[2]/ArcCsch[2] is 3?
• From: János <janos.lobb at yale.edu>
• Date: Wed, 21 Feb 2007 01:40:10 -0500 (EST)
• References: <200702201119.GAA07770@smc.vnet.net>

On Feb 20, 2007, at 6:19 AM, David W.Cantrell 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

My newbie instinct say that

IntegerPart[N[t]]+1

will do it :)

where t=ArcSinh[2]/ArcCsch[2]

Of course if you want just Real 3, than

N[t]

can be a friend.

J=E1nos


----------------------------------------------
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• References:
  • Showing that ArcSinh[2]/ArcCsch[2] is 3?
    • From: "David W.Cantrell" <DWCantrell@sigmaxi.net>