� |
Propriedades del n factorial n !: |
|
1 . |
n!
= n×
( n−
1 )
×
( n−
2 )
×
� × 3×
2 × 1
|
|
2 . |
0 !
=
1
|
|
3 . |
n!
= n×
( n−
1 )!
|
|
2 . |
⎛n⎞
⎛n⎞
⎜
⎟=
⎜
⎟=
1
⎝0⎠
⎝n⎠
|
3 . |
⎛n⎞
⎛ n
⎞
⎜
⎟=
⎜
⎟= n
⎝1⎠
⎝n
−1⎠
|
4 . |
⎛n⎞
⎛ n
⎞ nn
(
−1 )
�( n− r+
1 )
⎜
⎟=
⎜
⎟=
⎝r⎠
⎝n− r⎠ r!
|