[微積] 數列極限問題2則

看板Math作者 (嘿)時間14年前 (2011/08/17 23:25), 編輯推噓2(204)
留言6則, 3人參與, 最新討論串1/3 (看更多)
1. Suppose that an →L. Show that if an 小於等於 M for all n, then L 小於等於 M . 2. Let f be a function continuous everywhere and let r be a real number. Define a sequence as follows: a1=r , a2=f(r) , a3=f(f(r)) , ......... Prove that if an→L, then L is a fixed point of f:f(L)=L 這二題習題和同學討論許久不得其解 請版上高手解答 感謝! -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.112.240.34

08/17 23:26, , 1F
an 是數列的第n項 不好意思打不出下標的感覺
08/17 23:26, 1F

08/17 23:39, , 2F
f(L)=f(lim_{n->inf}a_n)=lim_{n->inf}f(a_n)
08/17 23:39, 2F

08/17 23:40, , 3F
=lim_{n->inf}a_{n+1}=L
08/17 23:40, 3F

08/17 23:40, , 4F
2.極限定義+連續函數定義想一下就是答案了
08/17 23:40, 4F

08/17 23:46, , 5F
1.假設L>M, choose e=(L-M)/2
08/17 23:46, 5F

08/17 23:51, , 6F
感謝啊,第二題原來不難XDD
08/17 23:51, 6F
文章代碼(AID): #1EIzrqE8 (Math)
文章代碼(AID): #1EIzrqE8 (Math)