作者apple4481 (apple)
看板Math
標題[代數] 一題代數
時間Mon Mar 21 17:18:53 2011
A ring R is called a Boolean ring if a^2=a.
Prove that every Boolean ring is commutative.
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1F：推 cnnie3719 :考慮(X+Y)^2=X+Y 03/21 17:25
2F：→ apple4481 :但是這樣會變成XY=-YX 吧 03/21 20:05
3F：推 bolyai :char(R)=2. 03/21 20:31
4F：推 yusd24 :-a=(-a)^2=a^2=a, 2a=0. (x+y)^2=x+y implies xy=yx 03/21 21:06
5F：→ apple4481 :謝謝!!! 03/22 19:05