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#1 2012-09-13 01:38:20

Agnishom
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From: The Complex Plane
Registered: 2011-01-29
Posts: 15,356
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Any recommendations?

I am going to appear at this olympiad:
Link

Since I am only in the 9th grade,
Would someone please suggest a way to improve my Mathematics?


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#2 2012-09-13 01:47:53

bobbym
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From: Bumpkinland
Registered: 2009-04-12
Posts: 83,211

Re: Any recommendations?

Hi Agnishom;

The olympiad questions are difficult. To increase you ability at solving problems there is only one way really. That is by doing problems.

I would like to see you participating more in the problems that are posed here. They will help turn you into a problem solver.

Since I am only in the 9th grade,

You are old enough for more.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#3 2012-09-13 02:31:56

Agnishom
Real Member
From: The Complex Plane
Registered: 2011-01-29
Posts: 15,356
Website

Re: Any recommendations?

Any good book that I can read?


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#4 2012-09-13 02:40:44

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 83,211

Re: Any recommendations?

You were asking about integer partitions on another forum. Do you know anything about generating functions?

Good books are very hard to find. Books that instruct are even harder to find. You can get good one on one instruction right here free.

Have you been continuing your work on that programming site?


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#5 2012-09-13 02:48:13

Agnishom
Real Member
From: The Complex Plane
Registered: 2011-01-29
Posts: 15,356
Website

Re: Any recommendations?

Have you been continuing your work on that programming site?

I am not sure which website you are talking about

Do you know anything about generating functions?

I am confused about that. I can only understand the recursive solution


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#6 2012-09-13 02:57:24

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 83,211

Re: Any recommendations?

Remember, Project Euler?

I am confused about that. I can only understand the recursive solution

First thing I would suggest is the same thing I do when conversing with anonimnystefy, I urge you to abandon the theoretical portion of math that they cram down your throat in school in favor of concrete problems.

Let's not talk about generating functions as a whole. Forget about the properties and fabulous theorems that theoretical mathematicians love. No one ever hires those guys, they hire problem solvers.

I asked on the other forum if you would post the problem. The real life problem which asks how may ways can you arrange this or that.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#7 2012-09-13 03:03:29

Agnishom
Real Member
From: The Complex Plane
Registered: 2011-01-29
Posts: 15,356
Website

Re: Any recommendations?

Yes, Project Euler!

Forget about the properties and fabulous theorems that theoretical mathematicians love. No one ever hires those guys, they hire problem solvers.

Why?
I want to learn Mathematics to gain knowledge and because I like it not because I want to get hired


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#8 2012-09-13 03:06:48

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 83,211

Re: Any recommendations?

Hi;

Would you rather know a lot of mathematics or be able to do a lot of mathematics?

Which is more important? Knowing every single proof by Euler or being able to solve problems that Euler solved? People think one thing leads to another but that is not true.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#9 2012-09-13 03:22:08

Agnishom
Real Member
From: The Complex Plane
Registered: 2011-01-29
Posts: 15,356
Website

Re: Any recommendations?

I understand now

People think one thing leads to another but that is not true.

Therefore, you do not believe in chain reactions?

Anyway, please explain generating functions


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#10 2012-09-13 03:44:58

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 83,211

Re: Any recommendations?

Therefore, you do not believe in chain reactions?

I believe in seeds. A small seed can grow into a large tree. Poison on the other hand does not promote growth. It just kills you.

If you want to compete in olympiads many of the problems will be combinatoric in nature. In combinatorics we count without counting.

Generating functions to make a point are never taught. What is taught are primitive methods of counting that rely on nCr's and nPr's. These are difficult for students to use and understand and therefore they do poorly. They end up hating mathematics and going into other fields.

Simply stated a generating function is a polynomial whose coefficients are integers and are the answers to many of the toughest combinatoric problems.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#11 2012-09-13 14:40:45

Agnishom
Real Member
From: The Complex Plane
Registered: 2011-01-29
Posts: 15,356
Website

Re: Any recommendations?

Generating functions to make a point are never taught. What is taught are primitive methods of counting that rely on nCr's and nPr's. These are difficult for students to use and understand and therefore they do poorly. They end up hating mathematics and going into other fields.

??
nCr's and nPr's are not that difficult!


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#12 2012-09-13 15:06:57

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 83,211

Re: Any recommendations?

When you have to do a tough combinatorics problem then they can be cumbersome. They rely on casework to get the answer which is really like counting which is what you are trying to avoid in combinatorics to begin with.

GF's on the other hand are just polynomial arithmetic which everyone understands and knows how to do.

I am not sure which website you are talking about

This is the one:

http://maths.freeforums.org/integer-partitions-t40.html


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#13 2012-09-14 02:13:15

Agnishom
Real Member
From: The Complex Plane
Registered: 2011-01-29
Posts: 15,356
Website

Re: Any recommendations?

The Problem was:
Let p(n) be the number of ways in which n number of coins can be split into piles.
Now, What is the minimum value of n which p(n) is divisible by one million.

I wish mathisfun.com had a page on GFs

Last edited by Agnishom (2012-09-14 02:30:43)


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#14 2012-09-14 05:24:30

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 83,211

Re: Any recommendations?

Hi Agnishom;

That problem is an unrestricted partition problem. You should start with Euler's pentagonal formula. But it will be difficult.

I wish mathisfun.com had a page on GFs

It may soon have one.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#15 2012-09-15 02:19:15

Agnishom
Real Member
From: The Complex Plane
Registered: 2011-01-29
Posts: 15,356
Website

Re: Any recommendations?

Please explain this one; I am not aware of the big Pi notation


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#16 2012-09-15 02:21:01

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 83,211

Re: Any recommendations?

That means a product instead of a series.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#17 2012-09-15 02:25:53

Agnishom
Real Member
From: The Complex Plane
Registered: 2011-01-29
Posts: 15,356
Website

Re: Any recommendations?


The series is infinite!!
But p(n) should be finite


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#18 2012-09-15 02:28:02

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 83,211

Re: Any recommendations?

That is a recurrence relation. If you want p(8) you you do not use anything past 8. In this case you would stop at p(7).


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Offline

#19 2012-09-15 02:28:52

Agnishom
Real Member
From: The Complex Plane
Registered: 2011-01-29
Posts: 15,356
Website

Re: Any recommendations?


Where is the number above the Sigma??


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#20 2012-09-15 02:30:39

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 83,211

Re: Any recommendations?

Sometimes, they mean it goes to infinity and they leave it out. Sometimes it goes to n and they leave it out. It really depends on the context.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#21 2012-09-15 02:37:53

Agnishom
Real Member
From: The Complex Plane
Registered: 2011-01-29
Posts: 15,356
Website

Re: Any recommendations?

So this is recursion; So would I get the error?

Maximum Recursion Depth reached

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#22 2012-09-15 02:40:02

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 83,211

Re: Any recommendations?

That is not exactly the same thing. In some languages that happens when you define a variable in terms of itself.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Offline

#23 2012-09-15 02:45:36

Agnishom
Real Member
From: The Complex Plane
Registered: 2011-01-29
Posts: 15,356
Website

Re: Any recommendations?

The identity implies a marvelous recurrence for calculating p(n), the number of partitions of n:

   

or more formally,

   

where the summation is over all nonzero integers k (positive and negative) and g_k is the kth pentagonal number.

But why p(n-7)??
7 isnt a pentagonal number


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#24 2012-09-15 02:48:22

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 83,211

Re: Any recommendations?

Hi;

You use the generalized pentagonal numbers. They are:

0, 1, 2, 5, 7, 12, 15, 22, 26, 35, 40, 51, 57, 70, 77, 92, 100,...

They are not the same as the pentagonal numbers.
The notation is really not doing anything but to obscure the beauty of Euler's idea. An example is worth 10000 lines of notation. Want to see one?


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Offline

#25 2012-09-15 02:58:30

Agnishom
Real Member
From: The Complex Plane
Registered: 2011-01-29
Posts: 15,356
Website

Re: Any recommendations?

Ya! ^_^


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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