Geometric sum of Convolution

👨🏻‍🏫 學術台數學

[匿名]

2011-10-01 12:17 pm

I just don't understand how this can be simplify to the answer, Please tell me step by step so I can learn from your steps.

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更新1:

u(n) is the unit step function

更新2:

To 自由自在: How can Sum(a^k x b^n-k) = b^n x Sum(a^k x b^-k)? why can I factor out the b^n out?

回答 (2)

用戶9112

2011-10-02 6:49 am

✔ 最佳答案

what is u(n), unit step function?

2011-10-01 22:49:53 補充：
http://i1090.photobucket.com/albums/i376/Nelson_Yu/int2-37.jpg

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2011-10-02 08:33:32 補充：
Within the summation, only k is changing. And a, b and n are constant. We can always
take out multiplicative constants out from the summation.

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[匿名]

2011-10-01 7:41 pm

oh yea I forgot. u(n) is unit step function

2011-10-02 02:37:46 補充：
To 自由自在:

How can Sum(a^k x b^n-k) = b^n x Sum(a^k x b^-k)?

why can I factor out the b^n out?

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收錄日期: 2021-04-23 23:25:40
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