http://imageshack.us/photo/my-images/838/0001ep.jpg/
可唔可以教我計一計？上面那題答案係 -9 但我計黎計去都係9
下面那題我rationalize 之後，個分母最終都係 0 。可唔可幫下我。
更新1:
仲有上面那題中 個infinity 係正係負其實都係咪一樣咁計？
Form 4 M2 Limits
2011-07-20 4:38 am
http://imageshack.us/photo/my-images/837/0001le.jpg/
http://imageshack.us/photo/my-images/838/0001ep.jpg/
可唔可以教我計一計？上面那題答案係 -9 但我計黎計去都係9
下面那題我rationalize 之後，個分母最終都係 0 。可唔可幫下我。
http://imageshack.us/photo/my-images/838/0001ep.jpg/
可唔可以教我計一計？上面那題答案係 -9 但我計黎計去都係9
下面那題我rationalize 之後，個分母最終都係 0 。可唔可幫下我。
回答 (1)
2011-07-20 5:02 am
✔ 最佳答案
5 lim(x-> -infinity) (9x - 4)/√(x^2 + 5x + 3)= lim(x-> -infinity) (9 - 4/x)/√(1 + 5/x + 3/x^2)
= 9/(-1)
= -9
17 lim(x-> infinity) √(4x^2 - x) + 2x
= lim(x-> infinity) -x /[√(4x^2 - x) - 2x]
= lim(x-> infinity) -1 /[√(4 - 1/x) - 2]
= 1/4
收錄日期: 2021-04-26 14:56:25
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110719000051KK01138