Determining Terms in $\sum_{n=-N}^{N}|e^{J\frac{\pi}{4}n}|^2$

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In summary: Sorry for the confusion. I counted the number of -ve values, positive values and zero separately. from -N to +N it is 2N+1 values.In summary, The summation from n = -N to N has 2N + 1 terms. This is determined by counting the number of negative, positive, and zero values in the range. The magnitude of the complex exponential function squared results in one.
  • #1
Drain Brain
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I just want to know how do I determine the number of terms will be in this summation. The answer to this 2N+1 terms. I can only arrive at preliminary steps of solving this. can you tell why 2N+1 is the number of terms? I know that the magnitude of complex exponential function squared would result to one.

$\sum_{n=-N}^{N}|e^{J\frac{\pi}{4}n}|^2$
 
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  • #2
Drain Brain said:


I just want to know how do I determine the number of terms will be in this summation. The answer to this 2N+1 terms. I can only arrive at preliminary steps of solving this. can you tell why 2N+1 is the number of terms? I know that the magnitude of complex exponential function squared would result to one.

$\sum_{n=-N}^{N}|e^{J\frac{\pi}{4}n}|^2$

as n is from -N to N the total number of terms is N ( -N to -1) + 1 ( zero) + N ( 1 to N) = 2N + 1

Within parenthesis I have mentioned the range
 
  • #3
kaliprasad said:
as n is from -N to N the total number of terms is N ( -N to -1) + 1 ( zero) + N ( 1 to N) = 2N + 1

Within parenthesis I have mentioned the range

Hi kaliprasad! How did you choose the range?
 
  • #4
Drain Brain said:
Hi kaliprasad! How did you choose the range?

In the sum that is (sigma) n is from -N to N and hence the range
 
  • #5
kaliprasad said:
In the sum that is (sigma) n is from -N to N and hence the range

why it is only -N to -1, 0, and 1 to N? I'm thinking of other ranges like -N to -2 etc.. I'm confused. Please help.
 
  • #6
Drain Brain said:
why it is only -N to -1, 0, and 1 to N? I'm thinking of other ranges like -N to -2 etc.. I'm confused. Please help.

Sorry for the confusion. I counted the number of -ve values, positive values and zero separately. from -N to +N it is 2N+1 values
 

FAQ: Determining Terms in $\sum_{n=-N}^{N}|e^{J\frac{\pi}{4}n}|^2$

What is the purpose of determining terms in a summation?

Determining terms in a summation allows us to analyze the behavior of a sequence or series, and understand the overall pattern and behavior of the terms.

How do you determine the terms in a summation?

To determine the terms in a summation, we first need to identify the general form of the terms, and then substitute different values for the index variable to find the corresponding values of the terms.

What does the notation $\sum_{n=-N}^{N}|e^{J\frac{\pi}{4}n}|^2$ represent?

This notation represents a summation of the squared absolute values of the terms in the sequence $e^{J\frac{\pi}{4}n}$, where $n$ ranges from $-N$ to $N$.

How can determining terms in a summation be useful in mathematics?

Determining terms in a summation can be useful in areas such as calculus, where it can help in finding the limit of a sequence or series, and in statistics, where it can be used to analyze the behavior of data over time.

Can the terms in a summation be determined using a formula?

Yes, in some cases, the terms in a summation can be determined using a formula or a pattern. However, in more complex cases, it may require a more thorough analysis and substitution of values to determine the terms.

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