The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » sci.math.* » sci.math

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Help with identity
Replies: 15   Last Post: May 9, 2013 7:13 AM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Robin Chapman

Posts: 412
Registered: 5/29/08
Re: Help with identity
Posted: Apr 26, 2013 9:31 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

On 26/04/2013 13:10, Mike Trainor wrote:

> Find the Fourier series expansion in y of
> sinh(x)/(cosh(x) - cos(y)).
> As I said in my first note, Bateman *gives* the answer
> by stating it without proof. I am looking for the proof.

As David said, summing the claimed answer to give
this function *is* a proof.

> It comes down to doing the integral of
> cos(ny)/(cosh(x) - cos(y))
> from 0 to 2 pi, for integer n, where x => 0.

How about integrating z^{n-1}/(cosh(x) - (z+1/z)/2)
over the unit circle in C?

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.