因打不出題目
故用圖片形式
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希望各位大大幫忙解答
工程數學之求收斂發散半徑
2009-05-09 9:46 pm
回答 (2)
2009-05-09 10:17 pm
✔ 最佳答案
Q1:| a(m+1)/a(m) | = | (m+2)x/m | --> |x| (as m->∞)
by ratio test: |x| < 1 => conv., |x|>1 => div.
so, the radius of conv. = 1
Q2:
Let y= (x-3)^2 /2
=> same as Q1:
By radius : | y | < 1 => conv.
i.e. | x- 3 | < √2 => conv.
so, the radius of conv. = √2
2009-05-09 9:55 pm
1. R = 1
2. R = sqrt(2)
2. R = sqrt(2)
收錄日期: 2021-04-23 23:04:38
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090509000015KK04483