Re: Trouble with an integral

*To*: mathgroup at smc.vnet.net*Subject*: [mg57403] Re: Trouble with an integral*From*: dh <dh at metrohm.ch>*Date*: Fri, 27 May 2005 04:56:40 -0400 (EDT)*References*: <d741q1$iff$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi Valeri, If you write the integrand in the form: Exp[-a x] ... rest containing no a it is clear that the integral should become smaller the larger a. We definitively have a bug here that Wolfram should take notice of. I beg Daniel Lichtblau to send a notice to the corresponding person. Sincerely, Daniel Valeri Astanoff wrote: > Bonjour le groupe, > > Could someone give me the right answer > for this integral with parameter 'a' ? > > In[1]:=$Version > > Out[1]=5.0 for Microsoft Windows (November 18, 2003) > > In[2]:=Integrate[Sqrt[1+Sqrt[x]]/(2*Sqrt[2]*E^(a*x)*Sqrt[x]),{x,0,1}, > Assumptions -> a>0] > > Out[2]=(1/3)*(4 - Sqrt[2]) > > In[3]:=%//N > > Out[3]=0.861929 > > In[4]:=NIntegrate[Sqrt[1+Sqrt[x]]/(2*Sqrt[2]*E^(2*x)*Sqrt[x]),{x,0,1}] > > Out[4]=0.491465 > > > > Thanks in advance. > > v.a. >