Re: [極限]一個求極限問題
※ 引述《JimCroce (我要下五子棋 N )》之銘言:
: 1 1
: lim [---------------- - ----------}
: x->0 ln(x+√(1+x^2)) ln(1+x)
: 請問這要怎樣做??
: 抱歉他上面沒標明是哪一年的考古!
ln(x+√(1+x^2)=(sinh^-1 x) = x+ x^3/6 +o(x) x->0
1 1 1 x
=> --------------- = --------------- = --- + --- +o(x) x->0
ln(x+√(1+x^2)) x- x^3/6 +0(x) x 6
ln(1+x)= x- x^2/2 +0(x) x->0
1 1 1 x
=> ------- = --- + --- + --- + o(x) x->0
ln(1+x) x 2 4
1 1
lim [---------------- - ----------}
x->0 ln(x+√(1+x^2)) ln(1+x)
1 x 1 1 x
lim [ ( --- + --- +o(x) ) - (--- + --- + --- + o(x) ]
= x->0 x 6 x 2 4
-1
= ---
2
---
如果有錯請指教 ^^
--
靈感 源自於累積已久的情緒
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 219.91.84.129
推
221.169.27.205 07/18, , 1F
221.169.27.205 07/18, 1F
推
210.58.172.85 07/18, , 2F
210.58.172.85 07/18, 2F
推
60.198.69.14 07/18, , 3F
60.198.69.14 07/18, 3F
→
60.198.69.14 07/18, , 4F
60.198.69.14 07/18, 4F
→
60.198.69.14 07/18, , 5F
60.198.69.14 07/18, 5F
推
210.58.172.85 07/18, , 6F
210.58.172.85 07/18, 6F
→
60.198.69.14 07/18, , 7F
60.198.69.14 07/18, 7F
推
219.91.84.129 07/18, , 8F
219.91.84.129 07/18, 8F
討論串 (同標題文章)