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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,615

Okay, I will help you with specific parts if you want it but if we get egg on our face...

**In mathematics, you don't understand things. You just get used to them.**

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**zetafunc.****Guest**

Oh boy, this doesn't look nice...

Looks like it's going to be a long night

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,615

Hi;

That will yield the inverse?

**In mathematics, you don't understand things. You just get used to them.**

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**zetafunc.****Guest**

It will at least give me the Cauchy principal value integral they are talking about,

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,615

Okay, let me know what you get.

**In mathematics, you don't understand things. You just get used to them.**

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**haron****Member**- Registered: 2011-09-27
- Posts: 1

hi everybody, i have got a doubt as to if laplace transform of (cos at)/t exists. if it doesnt, please explain as to why.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,615

Hi haron;

The transform of that does exist.

Welcome to the forum!

**In mathematics, you don't understand things. You just get used to them.**

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**nich****Guest**

doesnt tan(t) grow faster than an exponential? then cannot use laplace?

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,615

Hi nich;

Let's say that it does. Why does that mean you can not use the transform?

**In mathematics, you don't understand things. You just get used to them.**

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**zetafunc.****Guest**

I think L{tan(at)} doesn't exist because of its discontinuities.

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,615

Hi zetafunc.;

Yes, the infinite number of them.

**In mathematics, you don't understand things. You just get used to them.**

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**zetafunc.****Guest**

bobbym wrote:

Hi haron;

The transform of that does exist.

Welcome to the forum!

Is that supposed to be the Euler-Mascheroni constant? Where is that coming from?

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,615

Hi;

This was long ago and needs refreshing. That either comes from Alpha or a table. That is the Euler-Mascheroni constant.

**In mathematics, you don't understand things. You just get used to them.**

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**zetafunc.****Guest**

W|A is giving me that but without that constant. Can't really see where it would come from... I'll try the integration tomorrow.

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,615

Hi;

Alpha is not quite up to the stand alone program.

**In mathematics, you don't understand things. You just get used to them.**

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**zetafunc.****Guest**

I don't have the money for it yet.

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,615

Make sure you scan it well.

Probably that constant comes from the fact that the answer contains a series that equals it.

**In mathematics, you don't understand things. You just get used to them.**

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**zetafunc.****Guest**

Off the top of my head I can only think of the sum of the reciprocals of the natural numbers from 1 to n, minus log(n), as n tends to infinity. I know that yields the Euler-Mascheroni constant. I do not know of any others, maybe there are more.

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,615

Oh yes, there are many more! But no one knows whether it is irrational or not.

**In mathematics, you don't understand things. You just get used to them.**

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**zetafunc.****Guest**

Really? I did not know that. I just assumed it was irrational...

**zetafunc.****Guest**

The constant also comes out in the Laplace transform of natural log. Interesting.

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,615

You should like this one:

**In mathematics, you don't understand things. You just get used to them.**

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**zetafunc.****Guest**

Haha, it is the Zeta function! I am going to make a note of that one. I wonder how that can be proven.

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,615

Hi;

I do not remember but if I see it...

**In mathematics, you don't understand things. You just get used to them.**

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**zetafunc.****Guest**

I am looking at the wiki page now. There are lots involving the gamma function.