作者TibetFreedom (西藏自由加油!達賴加油!!)
看板Grad-ProbAsk
標題[理工] [微積] open subset closed subset 的問題
時間Tue Nov 3 19:41:45 2009
Let f be a real continuous function on a metric space S.
Let P(f)={s屬於S ▎f(s)＞0}
Is P(f) a closed subset,open subset,or neither？
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