Find c likes the series is convergent

  • Thread starter Thread starter marrie
  • Start date Start date
  • Tags Tags
    Convergent Series
Click For Summary
SUMMARY

The discussion focuses on determining the value of c ∈ IR for which the integral ∫₀^∞ (2x/(x²+1) - c/(2x+1)) dx converges. Participants suggest integrating the two components separately and analyzing their convergence behavior. Key insights include the necessity for the denominator to grow faster than the numerator for convergence, and the importance of finding a common denominator to simplify the expression. Ultimately, the discussion emphasizes the relationship between the growth rates of the numerator and denominator in integral convergence.

PREREQUISITES
  • Understanding of improper integrals and convergence criteria
  • Familiarity with calculus concepts, specifically integration techniques
  • Knowledge of limits and asymptotic behavior of functions
  • Ability to manipulate algebraic expressions and find common denominators
NEXT STEPS
  • Study convergence tests for improper integrals
  • Learn techniques for integrating rational functions
  • Explore the concept of asymptotic analysis in calculus
  • Practice finding common denominators in complex fractions
USEFUL FOR

Students and educators in calculus, mathematicians analyzing convergence of integrals, and anyone seeking to deepen their understanding of improper integrals and their convergence criteria.

marrie
Messages
2
Reaction score
0
Find c ∈ IR, like ∫∞ ( 2x - c ) dx is convergent
0 X^2 +1 2x+1

I need your help because I was trying to resolve the problem, but I couldn't, is difficult for me.
Please help me!
 
Physics news on Phys.org
Welcome to PF!

Hi marrie! Welcome to PF! :smile:
marrie said:
Find c ∈ IR, like ∫∞ ( 2x - c ) dx is convergent
0 X^2 +1 2x+1

hmm :rolleyes: … you mean \int_0^{\infty}\left(\frac{2x}{x^2+1} - \frac{c}{2x+1}\right)dx :wink:

Hint:

i] can you integrate each of them separately? does each converge or diverge?

ii] how much faster do you think the bottom needs to increase than the top for the integral to converge? :smile:
 
Ok, if I integrate each of them separately, I believe that the series diverge.
And I know that the bottom needs to increase than for the top for the integral converge.
thanks for your hints!
 
Hi marrie! :smile:
marrie said:
Ok, if I integrate each of them separately, I believe that the series diverge.
And I know that the bottom needs to increase than for the top for the integral converge.

ah … but how much more than the top? :wink:

anyway, write the whole thing over a common denominator …

then what does c have to be to make the top increase slowly enough? :smile:
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
7
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 48 ·
2
Replies
48
Views
6K
  • · Replies 6 ·
Replies
6
Views
2K