RE: This should evaluate to zero

*To*: mathgroup at smc.vnet.net*Subject*: [mg39969] RE: [mg39926] This should evaluate to zero*From*: "Wolf, Hartmut" <Hartmut.Wolf at t-systems.com>*Date*: Thu, 13 Mar 2003 03:03:45 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

>-----Original Message----- >From: jf.alcover at bdpme.fr [mailto:jf.alcover at bdpme.fr] To: mathgroup at smc.vnet.net >Sent: Wednesday, March 12, 2003 8:28 AM >To: mathgroup at smc.vnet.net >Subject: [mg39969] [mg39926] This should evaluate to zero > > >Bonjour, >Methinks that the following expression should evaluate to zero, >but it does not, even with FullSimplify : > ArcSinh[1]-Log[3363+2378*Sqrt[2]]/10 >Could anyone explain ? > If that helps: In[5]:= TrigToExp[ArcSinh[1]] == 1/10 Log[(1 + Sqrt[2])^10] Out[5]= True In[6]:= (1 + Sqrt[2])^10 // Expand Out[6]= 3363 + 2378*Sqrt[2] Such, what you think, is confirmed. -- Hartmut Wolf