→ gskman:補充一下Ix的意思類似 f(a)=a 這樣 11/19 23:09
四個element
可以想成
F^n n的order
4個 1-cycle =1
2個 1-cycle + 1個 2-cycle =2
2個 2-cycle =2
1個 1-cycle + 1個 3-cycle =3
1個 4-cycle =4
所以n最小為 12
※ 引述《askaleroux (aska)》之銘言：
: Let X be a set of four elements, and let Bx be the set of all
: bijective function from X to itself. Clearly, Bx!= none,since the
: identity map Ix from x to itself is in Bx. Let B be the set of positive
: integers n such that exist f belongs to Bx ,f^n=Ix.
: Let n be the smallest element of N. which of the following statements is true?
: n= 1,4,6,12
: n does not exist because N=none
: ========================================================================
: 答案是12
: 我想我的問題在於Ix我不知道是什麼碗糕
: 有大大能夠幫忙提點一下這一題解法嗎?
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