Integrals of Fourier Series
- Subject: [mg3179] Integrals of Fourier Series
- From: goster at nature.Berkeley.EDU (George Oster)
- Date: 14 Feb 1996 03:57:48 -0600
- Approved: usenet@wri.com
- Distribution: local
- Newsgroups: wri.mathgroup
- Organization: Wolfram Research, Inc.
- Sender: daemon at wri.com
Suppose I want to substitue a Fourier Series into an integral:
u[x_] := Sum[A[n] Sin[n Pi x/L], {n, 1, Infinity}]
Integrate[(u''[x])^2, {x, 0, L}]
This has an easy analytical solution that I can't get Mma to find, because
Mma doesn't know that Sum and Integrate commute, and that Sin[n
Pi] = 0 for all integer n.
How to do this?
GO
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Professor George Oster
University of California
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Email: goster at nature.berkeley.edu
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