Re: Integration
- To: mathgroup at smc.vnet.net
- Subject: [mg43955] Re: Integration
- From: "Curt Fischer" <crf3 at po.cwru.edu>
- Date: Wed, 15 Oct 2003 04:59:32 -0400 (EDT)
- References: <bmg0li$e9k$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Alex,
Spend some minutes going through the introductory help material in the Help
Browser.
Your definition for f defines it as a simple expression, not as a function
of one or more variables. But even after fixing this mistake, I couldn't
get Mathematica to return a value for the indefinite integral. Changing the
infinity to an arbitrary constant changed the result, though:
In[12]:=
Clear[f];
In[13]:=
\!\(\(f[\[Lambda]_] := \(\(\(2\) \(\[Pi]\)\(\ \)\(b\)\(\ \)\)\/a\) \((3 \(
e\^2\) \((x\/\[Lambda]\^2 + \(\[ImaginaryI]\ y\)\/\(\
\[Lambda]\^2 - e\^2\))\)
1\/\(\[Lambda] \((\[Lambda]\^2 - e\^2)\) \(\@\(\(a\^2\) \
\[Lambda]\^2 - l1\^2\)\) \@\(\(a\^2\) \[Lambda]\^2 - l2\^2\)\) - \(\((x\/\
\[Lambda]\^2 + \(\[ImaginaryI]\ y\)\/\(\[Lambda]\^2 - e\^2\))\)\^3\)
\(\(a\^2\
\) \(\[Lambda]\^3\) \((\[Lambda]\^2 - e\^2)\)\)\/\((\(\@\(\(a\^2\) \
\[Lambda]\^2 - l1\^2\)\) \@\(\(a\^2\) \[Lambda]\^2 - l2\^2\))\)\^3)\);\)\)
In[14]:=
Integrate[f, {\[Lambda], \[Xi], \[CapitalXi]}]
Out[14]=
f (-\[Xi] + \[CapitalXi])
Does that help any?
--
Curt Fischer
"Alex" <akhmel at hotmail.com> wrote in message
news:bmg0li$e9k$1 at smc.vnet.net...
> I tried to compute some elementary integrals (see below). Mathematica
> spent a couple of hours and didn't give any result. Any advice?
>
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> \(\(\(f = \(\(\(2\) \(\[Pi]\)\(\ \)\(b\)\(\ \)\)\/a\) \((3 \(
> e\^2\) \((x\/\[Lambda]\^2 + \(\[ImaginaryI]\
> y\)\/\(\
> \[Lambda]\^2 - e\^2\))\)
> 1\/\(\[Lambda] \((\[Lambda]\^2 - e\^2)\)
> \(\@\(\(a\^2\) \
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> \(\((x\/\
> \[Lambda]\^2 + \(\[ImaginaryI]\ y\)\/\(\[Lambda]\^2 - e\^2\))\)\^3\)
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> \) \(\[Lambda]\^3\) \((\[Lambda]\^2 - e\^2)\)\)\/\((\(\@\(\(a\^2\) \
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> Alex
>
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