How to Use Integration and Derivatives to Find the Sum of a Series

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The discussion focuses on using integration and derivatives to derive the sum of the series ∞ Σ (x2n-1)/(2n-1) from the Taylor series. The user successfully identifies the Taylor series for 1/(1-x) and substitutes x2 to obtain 1/(1-x2). They explore the relationship between integration and differentiation, noting that integration yields x2n+1/(2n+1) while differentiation results in 2n*x2n-1. The user concludes that by adjusting the limits of summation, they can manipulate the series to achieve the desired format.

PREREQUISITES
  • Understanding of Taylor series and their applications
  • Knowledge of calculus concepts, specifically integration and differentiation
  • Familiarity with series notation and manipulation
  • Basic algebra skills for handling expressions and limits
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  • Study the properties of Taylor series and their convergence
  • Learn advanced techniques in integration, particularly for series
  • Explore the relationship between integration and differentiation in calculus
  • Investigate other series summation techniques, such as generating functions
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Mathematicians, calculus students, and anyone interested in advanced series manipulation and the application of integration and derivatives in mathematical analysis.

Dell
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Σ (x2n-1)/(2n-1)
n=1

what i tried to do was take the taylor series:


Σ (xn)=1/(1-x)
n=1

so i can substitute x2 for x


Σ (x2n)=1/(1-x2)
n=1


now i need to to use some form of integration/derivative to get to my series from the taylor series,
my problem is that integral will give me x2n+1/(2n+1) , and derivative will give me 2n*x2n-1, but i need the format of the integration- a division format- but the numberss from the derivative- 2n-1 -
 
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Hint: Change the limits to n = 0 to ∞ and (2n - 1) to (2n + 1).
 
tell me if this is right


Σ x2n-1/(2n-1)
n=1
=

Σ x2(n+1)-1/(2(n+1)-1)
n=0
=

Σ x2n+1/(2n+1)
n=0

fx= 1/(1-x) = Σ xn
x==>x2
fx= 1/(1-x2) = Σ x2n

\intfx=\int1/(1-x2)=\intΣ x2n

0.5*ln|(1+x)/(1-x)| = x2n+1/2n+1

and i can do all of this because i say n=1, and n*=0, therefore n* goes from 0-∞ and n goes from 1-∞, making n*=n+1 so i can use the same taylor series, but instead of n, i write n+1
 
Ya looks good.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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