作者查詢 / Frobenius
作者 Frobenius 在 PTT [ Grad-ProbAsk ] 看板的留言(推文), 共77則
限定看板:Grad-ProbAsk
看板排序:
全部Physics1609Math433trans_math249DragonBall179sky140Prison_break134YUYUHAKUSHO130ONE_PIECE111Mathematica84Chemistry83Grad-ProbAsk77SD45Gossiping32PushDoll26D-grayman23Facebook18FacebookBM16Koei16FinalFantasy14Ancient13KS98-30213paranormal12X-files12GUNDAM10Translation10CYSH97Y3189Emulator9SRW9KS97-3158P2PSoftWare8STUST8YZU_CN99A8NUU_ER7Doraemon6joke6KOF6Linux6NTUCE-1016specialman6Suckcomic6AntiVirus5AOE5Rockman5SFFamily5FJ_Astroclub4Hunter4movie4SET4TKU_TSPCB934CS_TEACHER3FJU_physics3Instant_Mess3Militarylife3sex3ChineseMed2FJU_Psy962FTV2graduate2HatePolitics2HCHS593052historia2KS97-3022Lefty2MAC2Metal_kids2NetRumor2PeopleSeries2TaiwanDrama2TuTsau2AC_Music1Ang_Lee1ArakawaCow1Browsers1C_Chat1Chan_Mou1CHING1CHSH-93-3041CHSH-94-3191ck50th3231ck56th3041ck57th3201ck60th3301CKSC1cksh83rd3101CMU_MedEdu1Conan1CPU_CP7311CSMU-AC921CSMU-MIS921CTSH97EXP1CTV1CYCUEL95A1DeathNote1DiscoveryNGC1DummyHistory1EarthScience1finding1FJU-ACCR931FJU-ACCR941FJUecobasket1HCSHch13_3111HSNU_10951HSNU_9751Keelung1Mario1MCU_Talk1MIRAGE_LAB1MKSH-95-61NCCUEcoSport1NCKU-Chem1NCYU_CW_981NDHU-phy951NEHS19th41Nintendo1NTHUMathG1NTU1NTUCH-HW1NTUCL-BASKET1NTUE-DC991NTUE_Nse961NUU_Talk1Old-Games1PhD1PttLifeLaw1Python1regimen1RSSH93_3021RSSH93_3031SAN1SAN-YanYi1SlamDunk1TA_AN1TFSHS62th3051TFSHS65th3161TigerBlue1TKU_CE94C1TKU_trans1Tokusatsu1Transformers1TYSH48-3011WATARU1YP95-3131<< 收起看板(142)
3F推: http://tinyurl.com/hy2de3b04/12 00:48
1F推:推05/29 20:53
23F推:#1EIL6v9s (Math) Re: [微積] 幾個微分方程的觀念11/30 23:14
11F推:1. = EllipticE[π/2, k] (http://tinyurl.com/d99ayps)05/07 02:09
12F推:2. = EllipticF[π/2, k] (http://tinyurl.com/coxh5ra)05/07 02:11
13F→: = EllipticK[k] (http://tinyurl.com/d4xtr9d)05/07 02:14
14F推:P.S. EllipticF[Φ, k] (http://tinyurl.com/c8kqyqa)05/07 02:18
15F推:P.S. EllipticE[Φ, k] (http://tinyurl.com/2vbc65)05/07 02:20
16F推:P.S. EllipticE[π/2, k] (http://tinyurl.com/y8uken)05/07 02:25
17F→: = EllipticE[k]05/07 02:25
18F推:P.S. EllipticΠ[n;Φ, k] http://tinyurl.com/cknrwtg05/07 02:28
10F推:#1D0xyW7L (Math) [ptt.cc] Re: [工數] 一題ODE03/29 00:04
11F→:4.可以自己先偷算,如果是BesselJ(1/2,x)等類型可以再03/29 00:08
12F→:變換成三角函數等類型03/29 00:10
13F推:如果不是上述情形,先用Frobenius級數法找到指標方程03/29 00:14
14F推:(x^2)y''+(x^2+0.25)y=0 => y''+(1+0.25/^2)y=003/29 00:20
15F→:y''+ P(x)y'+ Q(x)y = 0 => P(x) =0,Q(x) = 1+ 0.25/x^203/29 00:22
16F推:(x^2)y''+(x^2+0.25)y=0 => y''+(1+0.25/x^2)y = 003/29 00:24
17F→:指標方程Po=0和Qo=1/4代入r(r-1)+Po*r+Qo=003/29 00:25
18F→:=> r (r - 1) + 1/4 == 0 => (r - 1/2)^2 = 003/29 00:27
19F推:r = 1/2 => 用傳統 Frobenius 級數的做法,或用03/29 00:30
20F→:y = √x*z(x) 代回原式整理得 x^2 z''+ x z'+ x^2 z = 003/29 00:31
21F→:z(x) = C1 BesselJ[0, x] + C2 BesselY[0, x]03/29 00:32
22F→:y(x) = √x(BesselJ[0, x] C[1] + BesselY[0, x] C[2])03/29 00:33
23F→:用傳統 Frobenius 級數的做法是可以得到 y1 的級數表示03/29 00:34
24F推:但遇到y2就要看情形 分三種情況 r2-r1≠0、0、整數03/29 00:41
25F推:r2-r1≠0的情況最容易,方法同 y1 的解03/29 00:45
26F推:http://tinyurl.com/d4l5jfa example:5.4-1303/29 00:56
27F→:r2-r1=0的情況則次之,y2為y1對r的偏微分再代入r03/29 01:01
28F→: example:5.4- 903/29 01:02
29F→:r2-r1=整數情況最麻煩 example:5.4- 3 and 503/29 01:06
30F→:example:5.4- 5、9、13 亦可用參數變異法得到03/29 01:10
31F→:http://tinyurl.com/pvzbwf03/29 01:10
34F→:example:5.4- 3 的y1為BesselJ,y2用此方法則難以積分03/29 01:12
35F→:除非用長除法再去積分可得y2的展開03/29 01:13
36F→:非線性部分用Talor或Frobenius法可能只能得到近似解03/29 01:14
37F→:而且可能還得去探討解的存在性跟唯一性再去看收斂區間03/29 01:14
39F→:u 要看是 u(y) or u(x) or u(x,y) ...03/29 01:16
41F→:只要u裡面出現y就可能是非線性,還得看變數是否能分離03/29 01:17
42F→:如果只有x跟y而已,雙方互為函數即反函數,就看對誰微分03/29 01:19
44F→: 及03/29 01:20
46F→:對 條件不足 沒辦法解03/29 01:21
48F推:至於 example:5.4- 3 and 5 的差別03/29 01:23
49F→:#1EIL6v9s (Math) Re: [微積] 幾個微分方程的觀念03/29 01:23
50F推:2.跟初始條件或邊界條件有關03/29 01:26
51F→:2.是正確的03/29 01:26
52F→:一樓正解03/29 01:27
54F推:先開http://tinyurl.com/3xjmo2603/29 01:58
55F→:再開http://tinyurl.com/d4l5jfa03/29 01:58
3F→:Mathematica跟我解的結果一樣(表示無法積分成初等函數)06/24 12:00
1F推:一階非線性常微分方程:http://tinyurl.com/7zt4lhe06/24 15:25
10F推:一樓doom大是神手10/21 18:51
11F推:#1HKeteZa (Grad-ProbAsk)[理工] [工數] O.D.E.問題集03/29 02:51
1F推:[分析] 去年台大碩士考題 (Math)09/29 18:41
9F推:推09/29 18:43