[Date Index] [Thread Index] [Author Index]

Re: Simplification question

• To: mathgroup at smc.vnet.net
• Subject: [mg110383] Re: Simplification question
• From: Adriano Pascoletti <adriano.pascoletti at uniud.it>
• Date: Wed, 16 Jun 2010 05:37:51 -0400 (EDT)

Considering the difference of the two sides the answer is returned
instantly


In[1]:== FullSimplify[1/2 Log[(Exp[a + b] + Exp[-a - b])/(Exp[-a + b] + Exp[a
- b])] -
  ArcTanh[Tanh[a] Tanh[b]], a =E2=88=88 Reals && b =E2=88=88 Reals]
Out[1]== 0


Adriano Pascoletti

2010/6/15 Yaroslav Bulatov <yaroslavvb at gmail.com>

> I'd like to verify that the following expression is true for a,b real.
> It seems to hold numerically.
>
> 1/2 Log[(Exp[a + b] + Exp[-a - b])/(Exp[-a + b] + Exp[a - b])] ====
> ArcTanh[Tanh[a] Tanh[b]]
>
> I tried Reduce and combinations of TrigToExp/Simplify with no luck,
> any suggestions?
>
>