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

  • Context: MHB 
  • Thread starter Thread starter Drain Brain
  • Start date Start date
  • Tags Tags
    Terms
Click For Summary
SUMMARY

The summation $\sum_{n=-N}^{N}|e^{J\frac{\pi}{4}n}|^2$ contains exactly 2N + 1 terms. This conclusion arises from counting the terms in the specified range of n, which includes N negative integers (from -N to -1), the zero term, and N positive integers (from 1 to N). The magnitude of the complex exponential function squared is equal to one, confirming that each term contributes equally to the sum.

PREREQUISITES
  • Understanding of complex exponential functions
  • Familiarity with summation notation
  • Basic knowledge of counting principles
  • Concept of magnitude in complex numbers
NEXT STEPS
  • Explore properties of complex exponential functions
  • Learn about summation techniques in mathematical analysis
  • Investigate the implications of magnitude in complex number calculations
  • Study counting principles in combinatorics
USEFUL FOR

Mathematicians, students studying complex analysis, educators teaching summation concepts, and anyone interested in understanding the properties of complex numbers and their applications in summation.

Drain Brain
Messages
143
Reaction score
0


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.

$\sum_{n=-N}^{N}|e^{J\frac{\pi}{4}n}|^2$
 
Physics news on Phys.org
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
 
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?
 
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
 
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.
 
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
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 14 ·
Replies
14
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
Replies
1
Views
2K
Replies
3
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K