[微積] 自然對數微積分
問個很基礎的問題= =|||
lnX^2 的微分是2/X ,把它積分回去是lnX^2 (應該沒錯吧
lnX^2 的積分怎麼算@_@?那積分完微分會一樣嗎?
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 120.114.118.84
推
11/19 19:02, , 1F
11/19 19:02, 1F
那請問lnX^2的積分是X(lnX)^2 +C 嗎?
我再微分完變成2lnX+(lnX)^2.............
※ 編輯: ohmygod0715 來自: 120.114.118.84 (11/19 19:29)
※ 編輯: ohmygod0715 來自: 120.114.118.84 (11/19 19:30)
推
11/19 19:30, , 2F
11/19 19:30, 2F
推
11/19 19:31, , 3F
11/19 19:31, 3F
推
11/19 19:31, , 4F
11/19 19:31, 4F
→
11/19 19:31, , 5F
11/19 19:31, 5F
我令u=lnx;du=1/x dx; xdu=dx
2∫lnx dx = 2∫ux du = u^2 *x =(lnx)^2 *x ................
請問這方法不能嗎ˊ_ˋ
我腦袋哪裡有洞
誰來幫我補補◢▆▅▄▃崩╰(〒皿〒)╯潰▃▄▅▇◣
※ 編輯: ohmygod0715 來自: 120.114.118.84 (11/19 20:02)
→
11/19 20:05, , 6F
11/19 20:05, 6F
推
11/19 20:07, , 7F
11/19 20:07, 7F
→
11/19 20:10, , 8F
11/19 20:10, 8F
阿~了解
所以只能用∫udv =uv-∫vdu 這解法吧@@
※ 編輯: ohmygod0715 來自: 120.114.118.84 (11/19 20:28)
→
11/19 20:39, , 9F
11/19 20:39, 9F
→
11/19 20:39, , 10F
11/19 20:39, 10F
→
11/19 20:44, , 11F
11/19 20:44, 11F
→
11/19 20:45, , 12F
11/19 20:45, 12F
→
11/19 21:03, , 13F
11/19 21:03, 13F
推
11/20 06:09, , 14F
11/20 06:09, 14F
→
11/20 06:10, , 15F
11/20 06:10, 15F
推
11/20 06:17, , 16F
11/20 06:17, 16F
→
11/20 06:18, , 17F
11/20 06:18, 17F
→
11/20 06:19, , 18F
11/20 06:19, 18F
→
11/20 06:20, , 19F
11/20 06:20, 19F
→
08/13 17:15, , 20F
08/13 17:15, 20F
→
09/17 15:10, , 21F
09/17 15:10, 21F
→
11/10 11:01, , 22F
11/10 11:01, 22F
→
11/10 11:01, , 23F
11/10 11:01, 23F
→
01/02 15:08,
5年前
, 24F
01/02 15:08, 24F