bibin
/
cphb
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Improve language

This commit is contained in:
Antti H S Laaksonen 2017-04-20 23:20:52 +03:00
parent 705a2e921b
commit 41a2e0c721
1 changed files with 5 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
chapter22.tex
View File

@ -112,8 +112,8 @@ Another way to calculate binomial coefficients is as follows:
There are $n!$ permutations of $n$ elements.
We go through all permutations and always
select the first $k$ elements of the permutation
to the subset.
include the first $k$ elements of the permutation
in the subset.
Since the order of the elements in the subset
and outside the subset does not matter,
the result is divided by $k!$ and $(n-k)!$
@ -124,10 +124,9 @@ For binomial coefficients,
\[
{n \choose k} = {n \choose n-k},
\]
because we can either select $k$
elements that belong to the subset
or $n-k$ elements that
do not belong to the subset.
because we actually divide a set of $n$ elements into
two subsets: the first contains $k$ elements
and the second contains $n-k$ elements.
The sum of binomial coefficients is
\[