[理工] [工數] 成大100

看板Grad-ProbAsk作者 (UTN)時間14年前 (2011/09/15 03:54), 編輯推噓1(104)
留言5則, 3人參與, 最新討論串1/4 (看更多)
成大工數100第一題 The first six Legendre polynomials are P0(x)=1 P1(x)=x P2(x)=1/2 (3x^2-1) P3(x)=1/2 (5x^3-3x) P4(x)=1/8 (35x^4-30x^2+3) P5(x)=1/8 (63x^5-70x^3+15x) Find the first three positive values of λ for which the problem (1-x^2)y'' - 2xy' + λy = 0 y(0)=0,y(x),y'(x) bounded on[-1,1] has nontrivial solutions (solutions other than y(x)=0) -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.114.206.124

09/15 12:36, , 1F
屬於有背有分的題目 λ=n(n+1)才有非零解 n為整數
09/15 12:36, 1F

09/15 12:37, , 2F
才會在 x = -1 及 x = 1 bounded 考試時再推來不及
09/15 12:37, 2F

09/15 22:15, , 3F
給予的邊界必須還要知道 λ = even 才有 y(0) = 0
09/15 22:15, 3F

09/15 22:15, , 4F
抱歉... λ = odd 才有XD
09/15 22:15, 4F

09/16 08:35, , 5F
謝謝樓上兩大大開示
09/16 08:35, 5F
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