→ metalalive:題目可能只要列出相異等價類就可以八 [1]=[4] 那 10/29 00:08
→ metalalive:[4] 就不必列出 10/29 00:08
On the set Z of all integers,define the relation R by
R = {(a,b)€ZXZ| a^2-b^2 is divide by 5}.
Show that R is an equivalence relation.
Find the equivalence classes of this equivalence relation on Z.
最後找等價類那邊
答案是[a]={b|b=5t +- a,t€z}
=>[0],[1],[2]
這邊不太了解..不是0~5都可以嗎= ="
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這邊我耍憨了...自己解
[0]=5t
[1]=5t+1,5t-1
[2]=5t+2.5t-2
[3]=5t+3,5t-3 等同於 5t-2,5t+2 = [2]
[4]=[1]
[5]=[0].....
所以是[0],[1],[2]
這樣解應該沒錯?
然後再推導那
我可以寫成[b]={a|a=5t +- b,t€z} 嗎?
感覺這樣寫比較順
等價讀的好爛阿= = 請求各位救援
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※ 編輯: genius945 來自: 114.40.243.158 (10/28 01:53)