How to swap real and imaginary parts and changing signs using Integrate
- To: mathgroup at smc.vnet.net
- Subject: [mg117673] How to swap real and imaginary parts and changing signs using Integrate
- From: Peter Pein <petsie at dordos.net>
- Date: Tue, 29 Mar 2011 06:58:03 -0500 (EST)
Hi group,
I observed the following strange behaviour:
In[1]:= intval=Integrate[ArcTanh[x]Sin[Pi x]
/x^(3/2),{x,-Infinity,Infinity}];
N[intval,20]
Out[2]= -1.25202170984968414370-0.44549963468032208018 I
In[3]:= NIntegrate[ArcTanh[x]Sin[Pi x]
x^(-3/2),{x,-Infinity,Infinity},WorkingPrecision->20,MaxRecursion->40]
Out[3]= 0.4454583760949374777+1.2524304857355799863 I
weird, isn't it?
Cheers,
Peter
P.S.: The CAS which must not be named here (you know which one):
evalf[20](Int(arctanh(x)*sin(Pi*x)/x^(3/2),x=-infinity..infinity));
0.44549963468032208018 + 1.2520217098496841437 I