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#1 2012-12-03 20:07:27

debjit625
Member
Registered: 2012-07-23
Posts: 89

Factorial Problem

I can't solve this one ...
Find n ,if

Thanks

Last edited by debjit625 (2012-12-03 20:08:48)


Debjit Roy
___________________________________________________
The essence of mathematics lies in its freedom - Georg Cantor

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#2 2012-12-03 20:10:39

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,771

Re: Factorial Problem

Hi;

n = 49.

Solve this:

(n+2)(n+1) = 2550


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 2012-12-03 20:13:04

bob bundy
Moderator
Registered: 2010-06-20
Posts: 6,126

Re: Factorial Problem

hi debjit625

So you just need to solve

Bob


You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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#4 2012-12-03 20:19:42

debjit625
Member
Registered: 2012-07-23
Posts: 89

Re: Factorial Problem

Ok I have seen this in my book too but ,I didn't understood how

expands into
,is their any special rules or am I missing something very basic


Debjit Roy
___________________________________________________
The essence of mathematics lies in its freedom - Georg Cantor

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#5 2012-12-03 20:21:31

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,771

Re: Factorial Problem

Hi;

(n+2)! = (n+2)(n+1)n (n-1)(n-2)(n-3)...1

n! =n (n-1)(n-2)(n-3)...1

(n+2)! = (n+2)(n+1)n!


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

#6 2012-12-03 20:32:41

debjit625
Member
Registered: 2012-07-23
Posts: 89

Re: Factorial Problem

Now I got it thanks guys, it was so simple ,my book didnt have enough of factorials its more about permutation can you guys give me some resource on factorials...

Thanks


Debjit Roy
___________________________________________________
The essence of mathematics lies in its freedom - Georg Cantor

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#7 2012-12-03 20:35:38

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,771

Re: Factorial Problem


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

#8 2012-12-03 20:39:49

debjit625
Member
Registered: 2012-07-23
Posts: 89

Re: Factorial Problem

I know about mathisfun ,I meant some advance stuff
Thanks again...


Debjit Roy
___________________________________________________
The essence of mathematics lies in its freedom - Georg Cantor

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#9 2012-12-03 20:41:24

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,771

Re: Factorial Problem

Hi;

Please check post #7, they get more and more difficult.


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

#10 2012-12-04 05:54:07

debjit625
Member
Registered: 2012-07-23
Posts: 89

Re: Factorial Problem

Thanks bobbym for the link http://www.themathpage.com/aprecalc/factorial.htm
as I was searching factorial problems involving variables and it had some great stuff.


Debjit Roy
___________________________________________________
The essence of mathematics lies in its freedom - Georg Cantor

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#11 2012-12-04 13:16:57

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,771

Re: Factorial Problem

Hi debjit625;

You are welcome.


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

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