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**Patrick****Real Member**- Registered: 2006-02-24
- Posts: 1,005

Would just like to point out that in Denmark we use y=ax+b

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**Ricky****Moderator**- Registered: 2005-12-04
- Posts: 3,791

In Virginia, we use:

Where p is a prime number.

*Last edited by Ricky (2006-02-28 09:05:17)*

"In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..."

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,560

Ha ha!

Tak for det, Patrick!

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**krassi_holmz****Real Member**- Registered: 2005-12-02
- Posts: 1,906

Cool, ricky where did you get this?

IPBLE: Increasing Performance By Lowering Expectations.

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**Ricky****Moderator**- Registered: 2005-12-04
- Posts: 3,791

I made it. Just simpily and you should get:

y/(ab) = x/b + 1/a, which of course is y = ax + b

"In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..."

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**Patrick****Real Member**- Registered: 2006-02-24
- Posts: 1,005

hehe, ricky - The reason I wrote this, was because of the request at the bottom of this page http://www.mathsisfun.com/equation_of_line.html

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**Ricky****Moderator**- Registered: 2005-12-04
- Posts: 3,791

Ah, ok, didn't know about that Patrick.

Well Mathisfun? Aren't you going to put mine on that page as well?

"In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..."

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**krassi_holmz****Real Member**- Registered: 2005-12-02
- Posts: 1,906

Ya, now when i"m looking this MONSTER equation it looks loke very simple.

Pretty good example how BEAUTIFUL maths can be.

IPBLE: Increasing Performance By Lowering Expectations.

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,560

Ricky wrote:

Well Mathisfun? Aren't you going to put mine on that page as well?

Do you think it will fit?

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**krassi_holmz****Real Member**- Registered: 2005-12-02
- Posts: 1,906

If it don't you can simplify it....

A little...

(You can call this "Ricky's approach")

IPBLE: Increasing Performance By Lowering Expectations.

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**nikconsult****Member**- Registered: 2006-08-04
- Posts: 48

In Malaysia we use y=mx+c

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**Zhylliolom****Real Member**- Registered: 2005-09-05
- Posts: 412

I've never heard of any of the equations in this thread. In my studies I have always used

where ζ is Riemann's zeta function, Γ(x) is the gamma function, ∇ is the del operator, L[sup]-1[/sup] denotes the inverse Laplace transform, T[sub]n[/sub] is the nth Chebyshev polynomial of the first kind, C is a simple closed curve bounding a region having z = a as an interior point, σ[sub]0[/sub][sup]m[/sup] is a simplex of an oriented simplicial complex and [σ[sup]m[/sup], σ[sup]m - 1[/sup]] is an incidence number, S is a compact, orientable, differentiable k-dimensional manifold with boundary in E[sup]n[/sup] and ω is a (k - 1)-form in E[sup]n[/sup], defined, and C[sup]1[/sup] at all points of S, and η(x) is Dirichlet's eta function.

(Sorry for stealing your joke, Ricky. )

*Last edited by Zhylliolom (2006-08-06 14:11:03)*

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,560

Ha! That's only the simplified version!

nikconsult: updated page, mentioned Malaysia: Equation of a Straight Line

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**Ricky****Moderator**- Registered: 2005-12-04
- Posts: 3,791

(Sorry for stealing your joke, Ricky. )

That should read: "Sorry for taking your joke too far."

Now your going to force me to go through and check the entire thing. And did I see a surface integral in there? I had a calc professor who said, "You should only think one thing whenever you see a surface integral and that's, 'AHHHHH!!!!'"

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**Zhylliolom****Real Member**- Registered: 2005-09-05
- Posts: 412

Making sure everything checks out would be a good exercise. After solving it, you'll realize that I made it rather simple... I should have made things crazier. Here are some things you can look into if you really want to see how it simplifies and get stuck: Elliptic integrals, obscure trigonometric identities, the Bromwich integral, obscure(and maybe somewhat non-obscure) infinite sums and products, definitions of obscure constants, contour integrals, simplicial homology theory, differential geometry, and integration of differential forms, just to name a few topics.

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**luca-deltodesco****Member**- Registered: 2006-05-05
- Posts: 1,470

in england, we tend to use y = mx + c

The Beginning Of All Things To End.

The End Of All Things To Come.

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**Ricky****Moderator**- Registered: 2005-12-04
- Posts: 3,791

is C², right Zylliolom?

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**Ricky****Moderator**- Registered: 2005-12-04
- Posts: 3,791

Isn't that supposed to be:

No? Assumming it is, I got:

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**Zhylliolom****Real Member**- Registered: 2005-09-05
- Posts: 412

No, **A** is an arbitrary vector. Just think about what the divergence of the curl is. I posted the formula for it in the Vector Formulas thread, but it should only take a moment to calculate it yourself.

Oh man, it's not letting me simply post "curl" again... and you're correct on the integral, I'll fix that typo right now.

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**Ricky****Moderator**- Registered: 2005-12-04
- Posts: 3,791

My book has that the divergence of a cur1 for any C^2 vector field F is 0... are you saying that C^2 is not needed?

And I got the same error when using cur1 as you did, hence the 1.

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**Zhylliolom****Real Member**- Registered: 2005-09-05
- Posts: 412

That's good so far.

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**Ricky****Moderator**- Registered: 2005-12-04
- Posts: 3,791

If anyone wants to jump in here and help me out (besides Zhylliolom), feel free.

Of course, correct me if you see any mistakes.

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**Zhylliolom****Real Member**- Registered: 2005-09-05
- Posts: 412

Wow, I don't know why I thought you meant C[sup]2[/sup] (as in some quantity or some vector) instead of **C**[sup]2[/sup].

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**Ricky****Moderator**- Registered: 2005-12-04
- Posts: 3,791

Cool integral. Is there a special name for it?

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**Zhylliolom****Real Member**- Registered: 2005-09-05
- Posts: 412

It's a special case of the polylogarithm known as the dilogarithm, this specific case is -Li[sub]2[/sub](1). Note that Li[sub]s[/sub](1) = ζ(s).

*Last edited by Zhylliolom (2006-08-06 15:08:59)*

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