Mathematics

Mathematics

Problem

For a fixed real parameter β\beta, examine the series R(β)=∑n=1∞n+βn2+1R(\beta)=\displaystyle \sum_{n=1}^{\infty} \dfrac{n+\beta}{n^{2}+1}. (a) Compute lim⁡n→∞n+βn2+1\displaystyle \lim_{n\to\infty} \dfrac{n+\beta}{n^{2}+1} in terms of β\beta. (b) Explain why the result from part (a) by itself neither confirms nor rules out convergence of R(β)R(\beta) for any value of β\beta. Provide a clear argument grounded in the properties of the limit you found. (c) Compare the general term of R(β)R(\beta) to 1n\dfrac{1}{n} for large nn, and discuss qualitatively what this comparison suggests about the convergence behavior of the series. No detailed proof beyond the discussion is required.

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