/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 86 For which values of \(p\) is \(\... [FREE SOLUTION] | 91Ó°ÊÓ

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For which values of \(p\) is \(\sum_{n=1}^{\infty}\left(\frac{n}{n^{2}+1}\right)^{p}\) convergent?

Short Answer

Expert verified
The series converges for values of \( p > 0 \).

Step by step solution

01

Understanding the Series

We are given the series \( \sum_{n=1}^{\infty}\left(\frac{n}{n^{2}+1}\right)^{p} \). To determine for which values of \( p \) this series is convergent, we will analyze the expression inside the series and its behavior as \( n \) becomes very large.
02

Simplifying the General Term

The general term in the series is \( \left(\frac{n}{n^{2}+1}\right)^{p} \). For large values of \( n \), this expression simplifies approximately to \( \left(\frac{n}{n^{2}}\right)^{p} = \frac{1}{n^{p+1}} \).
03

Applying the p-Series Test

We observe that for large \( n \), the series resembles a \( p \)-series of the form \( \sum_{n=1}^{\infty} \frac{1}{n^{p+1}} \). This series converges if \( p+1 > 1 \), or equivalently, if \( p > 0 \).
04

Conclusion about Convergence

Therefore, the given series \( \sum_{n=1}^{\infty}\left(\frac{n}{n^{2}+1}\right)^{p} \) converges for all \( p > 0 \). If \( p \le 0 \), the series diverges. Therefore, the series is convergent when \( p > 0 \).

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

p-Series Test
The p-series test is a popular method in mathematical analysis to determine the convergence of certain types of series. A p-series is defined as \( \sum_{n=1}^{\infty} \frac{1}{n^p} \), where \( p \) is a positive real number. The behavior of this series depends heavily on the value of \( p \).
  • If \( p \leq 1 \), the series diverges. This means it continues to grow indefinitely and does not settle at a finite value.
  • If \( p > 1 \), the series converges. It approaches a specific finite sum as you add more terms.
By applying this test, mathematicians can quickly determine whether a series like the one given in our exercise will converge or diverge depending on the value of \( p \). Understanding this principle aids in analyzing various series in calculus and other fields of mathematical studies.
Convergence Criteria
Convergence refers to the behavior of a series as more terms are added. To say a series converges means it approaches a finite limit. The basic idea is to understand if adding all the infinite terms gives a result that isn't infinite. Here, the p-series test gives us a simple criterion:
  • The series \( \sum_{n=1}^{\infty} \frac{1}{n^{p+1}} \) converges when \( p > 0 \).
This means that the value of \( p \) dictates the convergence. When \( p \leq 0 \), the terms do not get smaller fast enough to balance out the infinite addition, leading to divergence. The p-series essentially tells us how the size of the terms (based on \( p \)) impacts the series' behavior.
Mathematical Analysis
Mathematical analysis is the overarching field focusing on limits, continuity, and series. It provides the tools needed to study and understand series convergence. In the given problem, simplifying the general term was crucial. By analyzing \( \left(\frac{n}{n^{2}+1}\right)^{p} \) for large \( n \), we see that it approximates \( \frac{1}{n^{p+1}} \).This approximation allows us to utilize the p-series test. Such analysis not only involves simplifying terms but also understanding the fundamental properties of limits and functions. Through mathematical analysis, we decide when a series converges, offering valuable insights in mathematical, scientific, and engineering disciplines. This approach leads to powerful conclusions about infinite series, like in our exercise.

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Most popular questions from this chapter

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