數學問題-- 2 ! 等於咩

講學術 d

就一個非負整數 n 而言
n! = n * (n-1)!
or = 1 if n = 0
[即係 0! = 1]

咁例如
5! = 5 * 4!
= 5 * 4 * 3!
= 5 * 4 * 3 * ... * 1 * 0!
= 5 * 4 * 3 * 2 * 1 * 1

不過一般你乘到 1 都 ok 架喇

2! = 2 * 1 = 2

2=0 2
=1 1
=3-1
=4-2
=5-3
=6-4
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=6/3
=4/2
=8/4
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2!=1x2
.
. .1!=1
2!=1x2
3!=1x2x3
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2! in pure maths means
1*2

More example

0! = 1
1! = 1
2! = 1*2
3! = 1*2*3
4! = 1*2*3*4
....
n! = 1*2*3*4....*(n-1)*n