Re: [理工] [工數]-一題ODE
※ 引述《maikxz (超級痛痛人)》之銘言：
: 98台大應數C
: 2ty"+y'+2y=0
: 我是想到用級數解，除了級數解還有其它方式嗎？
: 謝謝
let t^1/2=u
y'=y`(1/2)-t^(-1/2)
y''=y``(1/4)t^-1 - 0.25 y`t^-3/2
->
0.5y``+2y=0
y``+4y=0
y=c1sin(2u)+c2cos(2u)
y=c1sin(2t^1/2)+c2cos(2t^1/2)
祝大家金榜題名:)
--
猛虎出閘,要比題目兇 .\ _ /. !!
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 123.193.214.165
推
02/26 21:01, , 1F
02/26 21:01, 1F
推
02/26 21:02, , 2F
02/26 21:02, 2F
→
02/26 21:04, , 3F
02/26 21:04, 3F
推
02/26 21:05, , 4F
02/26 21:05, 4F
→
02/26 21:06, , 5F
02/26 21:06, 5F
→
02/26 21:06, , 6F
02/26 21:06, 6F
推
02/26 21:09, , 7F
02/26 21:09, 7F
→
02/26 21:09, , 8F
02/26 21:09, 8F
→
02/26 21:11, , 9F
02/26 21:11, 9F
→
02/26 21:12, , 10F
02/26 21:12, 10F
推
02/26 21:14, , 11F
02/26 21:14, 11F
→
02/26 21:16, , 12F
02/26 21:16, 12F
→
02/26 21:17, , 13F
02/26 21:17, 13F
→
02/26 21:17, , 14F
02/26 21:17, 14F
→
02/26 21:18, , 15F
02/26 21:18, 15F
推
02/26 21:19, , 16F
02/26 21:19, 16F
→
02/26 21:20, , 17F
02/26 21:20, 17F
推
02/26 21:20, , 18F
02/26 21:20, 18F
→
02/26 21:21, , 19F
02/26 21:21, 19F
→
02/26 21:21, , 20F
02/26 21:21, 20F
→
02/26 21:22, , 21F
02/26 21:22, 21F
推
02/26 21:23, , 22F
02/26 21:23, 22F
推
02/26 21:25, , 23F
02/26 21:25, 23F
推
02/26 21:45, , 24F
02/26 21:45, 24F
→
02/26 21:46, , 25F
02/26 21:46, 25F
→
02/26 21:47, , 26F
02/26 21:47, 26F
→
02/26 21:48, , 27F
02/26 21:48, 27F
推
02/26 23:24, , 28F
02/26 23:24, 28F
→
02/26 23:24, , 29F
02/26 23:24, 29F
推
02/26 23:35, , 30F
02/26 23:35, 30F
→
02/26 23:36, , 31F
02/26 23:36, 31F
討論串 (同標題文章)