[其他] 一個很直觀但不知道怎麼說明的事情

看板Math作者 (女乃豆頁車侖)時間12年前 (2013/04/25 22:40), 編輯推噓5(5010)
留言15則, 7人參與, 6年前最新討論串1/1
假設 f是連續函數 且 f(1)=2 f(2)=1 則直線 y=x必經過這條直線 圖形上很好想,但是不知道怎麼轉成文字符號@@ -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 124.9.195.19

04/25 22:44, , 1F
Consider g(x)=f(x)-x, then g(1)=1, g(2)=-1
04/25 22:44, 1F

04/25 22:45, , 2F
then by IVT, there exists a c such that g(c)=0\
04/25 22:45, 2F

04/25 22:45, , 3F
c in (1,2)
04/25 22:45, 3F

04/25 22:46, , 4F
This means f(c)=c, i.e. f intersect with y=x
04/25 22:46, 4F

04/25 22:55, , 5F
看懂了!!!感謝!!
04/25 22:55, 5F

04/25 22:57, , 6F
推1F高微神手
04/25 22:57, 6F

04/25 23:04, , 7F
勘跟定理解之?
04/25 23:04, 7F

04/25 23:15, , 8F
勘根跟 IVT 是同一回事...
04/25 23:15, 8F

04/26 00:16, , 9F
其實這是微積分習題==
04/26 00:16, 9F

04/26 00:17, , 10F
我的高微也是THEJOY大教的喔>.^
04/26 00:17, 10F

08/13 17:35, , 11F
推1F高微神手 https://muxiv.com
08/13 17:35, 11F

09/17 15:28, , 12F
09/17 15:28, 12F

11/10 11:42, , 13F
Consider g( https://daxiv.com
11/10 11:42, 13F

01/02 15:22, 7年前 , 14F
Consider g( https://noxiv.com
01/02 15:22, 14F

07/07 10:55, 6年前 , 15F
勘跟定理解之? https://noxiv.com
07/07 10:55, 15F
文章代碼(AID): #1HUK1nY8 (Math)