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Ch. 10 - Infinite Sequences and Series
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077Non è quello che usi tu?Cambia libro di testo
Capitolo 10, Problema 10.PE.18

Determining Convergence of Sequences
Which of the sequences whose nth terms appear in Exercises 1–18 converge, and which diverge? Find the limit of each convergent sequence.


aₙ = (-4)ⁿ/n!

Guida verificata passo dopo passo
1
Identify the general term of the sequence: \(a_n = \frac{(-4)^n}{n!}\).
Recall that \(n!\) (n factorial) grows much faster than any exponential function \(c^n\) as \(n\) approaches infinity.
To determine convergence, analyze the limit \(\lim_{n \to \infty} \frac{(-4)^n}{n!}\).
Since the factorial in the denominator grows faster than the exponential in the numerator, the terms \(a_n\) approach zero as \(n\) becomes very large.
Conclude that the sequence converges and its limit is \(0\).

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A sequence converges if its terms approach a specific finite value as n approaches infinity. Determining convergence involves analyzing the behavior of the nth term and checking if the limit exists and is finite.
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Factorials (n!) grow much faster than exponential functions like (-4)^n. Understanding the relative growth rates helps in evaluating limits involving factorials and powers, often leading to convergence when factorials dominate.
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Limit of a Sequence

The limit of a sequence aₙ is the value that aₙ approaches as n becomes very large. Calculating this limit often involves applying limit laws, comparing growth rates, or using known limits of standard sequences.
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