Sum the Binomial Series: C_0^2-2C_1^2+...+(-1)^n(n+1)C_n^2

In summary, the conversation is discussing how to sum a series up to N terms, specifically the series C_0^2-2C_1^2+...+(-1)^n(n+1)C_n^2. The person is struggling with finding the coefficient of a specific term and does not want to provide a proof of their work at the moment. They are also seeking help on how to evaluate similar series in the future. Suggestions are given to use (1-x)^n and (1+x)^n and to look at multiplication and differentiation. The conversation ends with the person still struggling with finding the square of the coefficients.
  • #1
chaoseverlasting
1,050
3

Homework Statement


Sum the following series to N terms:
[tex]C_0^2-2C_1^2+...+(-1)^n(n+1)C_n^2[/tex]

Arrgh! This is a very frustrating question. I have to multiply two series and find the coefficient of some term but I don't know what to do. Please don't ask me to give you some proof of my work at this point of time.


Homework Equations



[tex](1+x)^n=C_0+C_1x+C_2x^2...Cnx^n[/tex]
 
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  • #2
Also if someone could tell me how to evaluate series of such sort in the future. I suck at this.
 
  • #3
firstly, what you have been given is not a series, a series in an infinite sum.. yours is partial sum up to n. by the way it may help to write out the Cn's in terms of n.
 
  • #4
hint:

1. [tex](1-x)^n[/tex]

2. look at multiplication by x, and differentiation.

3. play with functions first, then substitute in x=1
 
Last edited:
  • #5
Yeah.. I did the multiplication by x and the differentiation. I already tried that. What I don't get is how to get the square of the coefficients.
 
  • #6
look at coefficients in
[tex](1-x)^n(1+x)^n[/tex]
 

FAQ: Sum the Binomial Series: C_0^2-2C_1^2+...+(-1)^n(n+1)C_n^2

What is the purpose of summing the binomial series?

The purpose of summing the binomial series is to find the value of a specific term or the entire series, which can be useful in various mathematical calculations and applications.

What does the notation C_n^2 mean in the series?

The notation C_n^2 represents the combination of n objects taken 2 at a time, also known as the binomial coefficient. It is calculated using the formula n!/(2!(n-2)!).

How is the series typically represented?

The series is typically represented using the summation notation, which is written as ∑ (-1)^n(n+1)C_n^2. This means that each term is added together, starting from n=0 and continuing until a specific value is reached.

What is the significance of the alternating signs in the series?

The alternating signs in the series (-1)^n represent the pattern of the terms, where every other term is subtracted instead of added. This is a characteristic of binomial series and is used to simplify calculations and find specific values.

How can the sum of the binomial series be calculated?

The sum of the binomial series can be calculated using various methods, such as the binomial theorem or manipulating the series into a known mathematical formula. It can also be approximated using numerical methods or by using a calculator or computer program.

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