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討論串[問題] Lagarangian自變數是獨立的？
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Your conterexample is very good, and I have to give a little. supplement. Since η(x) can be any continous function ,but in functional. analysis about
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This statement is not true since there is a counterexample:. Let [a,b] = [-1,1]. Let f(x) = sin(pi*x) for all x on [-1,1]. Let η(x) = exp(-(1/(1-x^2))
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δS = ∫[(d/dq)L - (D/Dt)(d/dv)L ] δq dt. It's should be (d/dq)L-(D/Dt)(d/dv)L=0. 你會證明這個式子嗎? 我猜99%的物理系學生沒念過V.I.Arnold的古典力學. 應該都會把這步視為trivial,事實上這一點都不tri
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why?. 我剛剛貼錯了,應該是這一行. δS = δ∫L(q,v,t) dt. = ∫[(d/dq)L δq + (d/dv)L δv] dt (d是偏微分). 1. δS=0這裡有積分喔,而且是上下限給定的積分,你怎麼證明下列. (d/dq)L=0, (d/dv)L=0 給個證明,你寫太簡略了.
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