Re: do u know how to calculate this integral?


<linhthanh2006@xxxxxxxxx> wrote in message
news:1148483310.915779.316090@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Dear all,

Do u know how to calculate this integral: integral (from 0 to 1) of
(x^k*(1-x)^(n-k)dx?

1-|
| x^k * (1-x)^(n-k) dx
|- 0

I know the result is (n-k)!k!/(n+1)!, but get difficulty to derive it
to the result.

Thanks


Integrate (1 - x + xy)^n w.r.t. x, from x=0 to x=1.

The coef. of y^k, divided by C(n,k), is your answer.


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