Re: This should evaluate to zero

*To*: mathgroup at smc.vnet.net*Subject*: [mg40009] Re: This should evaluate to zero*From*: Bill Rowe <listuser at earthlink.net>*Date*: Fri, 14 Mar 2003 04:47:51 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

On 3/13/03 at 3:06 AM, atelesforos at hotmail.com (Orestis Vantzos) wrote: >Actually, ArcSinh[1] is equal to Log[1+Sqrt[2]] Orestis In[1]:= Exp[Log[3363+2378*Sqrt[2]]/10]-Exp[- Log[3363+2378*Sqrt[2]]/10]//PowerExpand//FullSimplify Out[1]= 2 So, the original poster's expectation for ArcSinh[1]-Log[3363+2378*Sqrt[2]]/10 to simplify to zero is not unreasonable. I assume the reason FullSimplify did not reduce this expression to zero is there aren't rules built in to relate ArcSinh to expressions with Log.