1/(3^(k) + 5)
I don t know how to work with exponents.
Show that the series converges by using comparison test?
2016-06-23 9:03 am
回答 (1)
2016-06-23 1:29 pm
✔ 最佳答案
By comparing with the convergent geometric series Σ 1/3^k ,Σ 1/( 3^k + 5 )
= 1/( 3 + 5 ) + 1/( 3^2 + 5 ) + ..... + 1/( 3^k + 5 ) + .....
< 1/3 + 1/3^2 + ..... + 1/3^k + .....
= (1/3) / ( 1 - 1/3 )
= (1/3) / (2/3)
= 1/2
Hence, Σ 1/( 3^k + 5 ) converges.
Q.E.D.
收錄日期: 2021-05-02 14:11:25
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160623010344AAVzQl0