[工數] 傅立葉轉換 平移定理
-ax
f(x)=H(x)e , H(x) is the Heaviside step function and a>0,
求F{f(x)}=?
我的做法
先轉換H(x)
∞ -iωx ∞ -iωx 1
F{H(x)} = ∫ H(x)e dx= ∫ 1*e dx = ------
-∞ 0 iω
使用平移定理
-ax 1
F{f(x)} = F{H(x)e } = ----------
i(ω+a)
1
但是解答是 ------- 請問以上我的步驟哪邊出錯了? 謝謝
a+iω
--
※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 101.14.7.8
※ 文章網址: https://www.ptt.cc/bbs/Math/M.1444837478.A.6B0.html
→
10/14 23:51, , 1F
10/14 23:51, 1F
→
10/14 23:53, , 2F
10/14 23:53, 2F
→
10/15 01:21, , 3F
10/15 01:21, 3F
→
10/15 02:37, , 4F
10/15 02:37, 4F
→
10/15 02:39, , 5F
10/15 02:39, 5F
→
10/15 02:39, , 6F
10/15 02:39, 6F
推
10/15 09:51, , 7F
10/15 09:51, 7F
→
10/15 09:52, , 8F
10/15 09:52, 8F
→
10/15 11:17, , 9F
10/15 11:17, 9F
→
10/15 21:46, , 10F
10/15 21:46, 10F
→
10/15 22:51, , 11F
10/15 22:51, 11F
→
10/15 22:52, , 12F
10/15 22:52, 12F
→
10/15 22:53, , 13F
10/15 22:53, 13F
→
10/15 23:54, , 14F
10/15 23:54, 14F
→
10/15 23:55, , 15F
10/15 23:55, 15F
→
10/16 09:22, , 16F
10/16 09:22, 16F
→
10/16 09:23, , 17F
10/16 09:23, 17F
→
10/16 09:23, , 18F
10/16 09:23, 18F
→
10/18 13:20, , 19F
10/18 13:20, 19F