[領域]普物                             (題目相關領域)

[來源]serway 6th  26-74                 (課本習題、考古題、參考書...)

[題目]
Yoy are optimizing coaxial cable design for a major manufacturer.
Show that for a given outer conductor radius b, maximum potential
difference capability is attained when the radius of the inner
conductor is a=b/e where e is the base of natural logarithms.


[瓶頸]                             (寫寫自己的想法，方便大家為你解答)
http://www.zshare.net/image/8829355f8ecef1/  (這是網路上標準答案)
但a越小電位差不是越大?
為何在題目�u a=b/e
會有最大值
而且正解的Emax不也是a的函數   在對a微分時為何沒對Emax微?
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◆ From: 140.113.20.11
※ 編輯: GOTOJOHN0       來自: 140.113.20.11        (03/12 23:03)