complex output for real integral
- To: mathgroup at smc.vnet.net
- Subject: [mg115843] complex output for real integral
- From: Ted Sariyski <tsariysk at craft-tech.com>
- Date: Sat, 22 Jan 2011 03:23:34 -0500 (EST)
Hi,
I get complex answer for an integral from Exp[1/x^3]/x^3 over the real
axes:
In[]:=f[n_] = Assuming[
{Element[x, Reals], Element[n, Integers], n >= 1},
Integrate[E^(1/x^3)/x^3, {x, n, Infinity}]
]
Out[]:= 1/6 (-1)^(1/3) (-3 Gamma[5/3] + 2 Gamma[2/3, -(1/n^3)])
The imaginary part of f[n] is everywhere ~10^-16 and I could ignore
it but I guess there is a better approach.
I'll appreciate any help.
--Ted