Re: Binomial coefficient
- From: Han de Bruijn <Han.deBruijn@xxxxxxxxxxxxxx>
- Date: Thu, 13 Sep 2007 14:21:32 +0200
Denis Feldmann wrote:
Han de Bruijn a écrit :
Denis Feldmann wrote:
Han de Bruijn a écrit :
desktop wrote:
In a book I am reading the Binomial coefficient is defined as:
(n k) = n^(k)/k! = n!/(k!*(n-k)!)
But if I try with this example:
(10 3)
I get, using "n^(k)/k!":
10^3/6 = 166.66666
Using "n!/(k!*(n-k)!)" I get:
10!/(3!*7!) = 120
But should the two equations not give the same result?
Not if the first one [ n^(k)/k! ] is simply wrong.
As usual;,you are extremely pertinent and useful. Did you notice that n^(k) is not written the same as n^k ? Could it be you are missing somrthing there (like the notation x^(k)=x(x-1)(x-2)...(x-k+1) )?
Something? As well as the OP, I've never seen this notation, indeed ..
Try reading a book or two, like "Concrete Mathematics" (Graham, Knuth, Patashnik) (ok, usually, as in those books, this is written x^"undescored k"). But anyway, I ibsist : when one reads 4^(3), he must suspect that this is not hte same as 4^3 (or see "Leibnitz formula" : f^(n) is tne n-th derivative of f, not the n-th power...)
Ah, I see: n^(k) is the k-th derivative of n. Thanks! :-)
And ab = a times b. Thus 43 = four times three and 1 1/2 = 1 times 1/2,
not 1 + 1/2. It may be all very confusing for a beginner in mathematics
(no kidding).
Han de Bruijn
.
- References:
- Binomial coefficient
- From: desktop
- Re: Binomial coefficient
- From: Han de Bruijn
- Re: Binomial coefficient
- From: Denis Feldmann
- Re: Binomial coefficient
- From: Han de Bruijn
- Re: Binomial coefficient
- From: Denis Feldmann
- Binomial coefficient
- Prev by Date: Re: JSH: Triumph of stupidity
- Next by Date: Re: Two results of set geometry
- Previous by thread: Re: Binomial coefficient
- Next by thread: Re: Binomial coefficient
- Index(es):
Relevant Pages
|