I understand how to find them when numbers are involved. However, my problem is I can not figure out how to do it with n terms.

Example:

$\displaystyle \frac{(2n)!}{(2n-2)!}$

Any help will be greatly appreciated.

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- Apr 27th 2008, 07:30 AMmathgeek777Factorials
I understand how to find them when numbers are involved. However, my problem is I can not figure out how to do it with n terms.

Example:

$\displaystyle \frac{(2n)!}{(2n-2)!}$

Any help will be greatly appreciated. - Apr 27th 2008, 07:38 AMIsomorphism
- Apr 27th 2008, 07:38 AMKai
Hmm, try using the fact that n!= n(n-1)!=n(n-1)(n-2)!

- Apr 27th 2008, 07:41 AMelizsimca
- Apr 27th 2008, 07:44 AMfinch41
i dont know how sound this logic is since i haven't done factorials in a long time but maybe it will steer you in some sort of direction

(2n)!

------

(2n-2)!

gives:

1x2x3...x(2n-3) x(2n-2) x (2n-1) x (2n)

--------------------------------------

1x2x3...x((2n-2)-1) x (2n-2)

this leaves (2n-1)(2n) - Apr 27th 2008, 07:45 AMmathgeek777
So the answer is 2n(2n-1)?

- Apr 27th 2008, 07:47 AMelizsimca
- Apr 27th 2008, 07:51 AMfinch41
try it out, test the values n = 3,4,5 first by inserting in the original expression and expanding and simplifying and then second by inserting the values n into 2n(2n-1) and you should get the same answer