精華區beta Math 關於我們 聯絡資訊
1. Suppose that |f|^p is Riemann (improper) integrable over the domain Ω p (but not continuous) , does f belong to L (Ω)? To be more precise , for such an f , is there a sequence f belonging to C(Ω) so that k p lim ∫ |f (x) - f(x)| dx = 0 ? k→∞ Ω k 2. Is there any function which is not Riemann (improper) integrable but is a ||˙|| limit of continuous function ? p n p 3. Suppose Ω is contained in R , and f belongs to L (Ω) . Is there a ∞ p sequence of smooth functions {f_k} so that f → f in L (Ω) k=1 k as k→∞ ? n 4. For Ω contained in R open , for ε>0 sufficiently small , define the open subset Ω of Ω by ε Ω = { x belongs to Ω | dist(x , boundry of Ω) > ε} . ε ∞ n Define η belonging to C (R ) by { C(e^(1/(|x|^2 - 1))) if |x| < 1 η(x) = { { 0 if |x| ≧ 1 with constant C > 0 chosen such that ∫ η(x) dx = 1 . R^n For ε> 0 , the standard sequence of mollifiers is defined by η = (ε^(-n))(η(x/ε)) . ε Prove that ∫ η (x) dx = 1 R^n ε _______ and supp(η ) is contained in B(0,ε) ε 5. Prove that all norms on R^n are equivalent . 以上這5題實變 請會的人幫我寫出詳細的證明過程 謝謝 Q.Q -- 本週抽中:安 心 亞 本週最心碎:吳 怡 霈 本週最亮眼:王 薇 欣 動園木萬社萬醫辛 麟六犁科大大忠復南東中國松機劍路西港內大公葫東南軟園南展 物 柵芳區芳院亥 光技樓安孝興京路山中山場湖墘湖湖園洲湖港體區港覽 ○ ○○ ○ ○ ○◎◎ ◎ ○○○○ ○◎○ ◎館 王樺邵艾絲小樺張甯莎王欣李慧啾豆妹安亞吳霈廖嫻徐翊舒虎可蜜兒蔓小劉萍 林玲 彩 庭莉 欣 鈞 拉啾花 心 舒牙樂雪 蔓蔓秀 志 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.115.189.53
doubleN :3. (f*η_ε) → f 10/01 21:08
doubleN :4.變數變換 10/01 21:08
doubleN :5.請參考泛函書籍 10/01 21:09