Re: Why does this happen?
- To: mathgroup at smc.vnet.net
- Subject: [mg78724] Re: Why does this happen?
- From: dh <dh at metrohm.ch>
- Date: Sat, 7 Jul 2007 06:15:12 -0400 (EDT)
- References: <f6ks38$lbm$1@smc.vnet.net>
Hi Budaoy, look at your integrand. For large x you can neglect 1 and get Log[Exp[x]/Sqrt[x], but this is Log[Exp[x]]-Log[Sqrt[x]], where the first part is mach larger than the second. Therefore the integrand is approx.: x. This means, the integral does not exisit. hope this helps, Daniel Budaoy wrote: > I have a problem in calculating this integral shown below: > > Integrate[Log[1+Exp[x]/Sqrt[x]],{x,0,Infinity}] > Pi^2/6 > > N[%] > 1.64493 > > NIntegrate[Log[1+Exp[x]/Sqrt[x]],{x,0,Infinity}] > 1.01799 > > Where does this difference come from and which one is correct? > >