a-maths~!!!!!
2008-07-02 2:13 am
回答 (2)
2008-07-02 3:21 am
✔ 最佳答案
let k= (4+x)/(4-x)4k - kx= 4 + x
4(k-1 ) = x( k+1)
x/4 = (k-1)/ (k+1) = 1 - 2/( k+1)
so, lim( x->4) x /4 = 1 = 1- 2/( k+1)
as there is no solution of k , lim( x->4) (4+x)/(4-x) is no defined .
2008-07-01 19:22:59 補充：
可用上極限and下極限來做,
check下 lim(x-> +4 ) f(x) = lim(x-> -4) f(x) ???
2008-07-02 6:27 am
Put x=4 into the fraction, which is not in the form of 0/0, infinity/0, or 0/infinity, which implies that the limit does not exists
收錄日期: 2021-04-23 20:35:09
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080701000051KK02113