Skip to main content
Ch. 10 - Sequences and Infinite Series
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Non è quello che usi tu?Cambia libro di testo
Capitolo 10, Problema 10.7.87a

Explain why or why not
Determine whether the following statements are true and give an explanation or counterexample.
a. If the Limit Comparison Test can be applied successfully to a given series with a certain comparison series, the Comparison Test also works with the same comparison series.

Guida verificata passo dopo passo
1
Recall the definitions of the Comparison Test and the Limit Comparison Test for series convergence: The Comparison Test requires that the terms of the given series and the comparison series satisfy an inequality for all sufficiently large indices, while the Limit Comparison Test uses the limit of the ratio of their terms as the index approaches infinity.
For the Comparison Test, you need to find a comparison series \( \sum b_n \) such that either \( 0 \leq a_n \leq b_n \) or \( 0 \leq b_n \leq a_n \) for all \( n \) beyond some index, and then use the known convergence or divergence of \( \sum b_n \) to conclude about \( \sum a_n \).
For the Limit Comparison Test, you compute \( \lim_{n \to \infty} \frac{a_n}{b_n} = c \), where \( c \) is a finite positive number. If this limit exists and is positive and finite, then both series either converge or diverge together.
Consider that the Limit Comparison Test can succeed even if the inequality required for the Comparison Test does not hold for all large \( n \). This means the Comparison Test might fail to apply with the same comparison series even though the Limit Comparison Test works.
Therefore, the statement is false: the successful application of the Limit Comparison Test with a certain comparison series does not guarantee that the Comparison Test will also work with the same comparison series. A counterexample can be constructed where the limit of the ratio exists and is positive, but the inequality needed for the Comparison Test fails.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
5m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Limit Comparison Test

The Limit Comparison Test determines the convergence or divergence of a series by comparing it to a second series with known behavior. It involves taking the limit of the ratio of their terms; if the limit is a positive finite number, both series either converge or diverge together.
Video consigliato:
Percorso guidato
07:45
Limit Comparison Test

Comparison Test

The Comparison Test assesses a series' convergence by directly comparing its terms to those of a known convergent or divergent series. If the terms of the original series are smaller than a convergent series, it converges; if larger than a divergent series, it diverges.
Video consigliato:
Percorso guidato
09:25
Direct Comparison Test

Differences Between Limit Comparison and Comparison Tests

While both tests compare series, the Comparison Test requires strict inequalities between terms, which can be restrictive. The Limit Comparison Test is more flexible, relying on the limit of term ratios, so it can succeed even when direct inequalities needed for the Comparison Test do not hold.
Video consigliato:
Percorso guidato
07:45
Limit Comparison Test
Pratica correlata
Domanda del libro di testo

57–60. Heights of bouncing balls A ball is thrown upward to a height of hₒ meters. After each bounce, the ball rebounds to a fraction r of its previous height. Let hₙ be the height after the nth bounce. Consider the following values of hₒ and r.


a. Find the first four terms of the sequence of heights {hₙ}.


h₀ = 30,r = 0.25

54
views
Domanda del libro di testo

{Use of Tech} Drug Dosing

A patient takes 75 mg of a medication every 12 hours; 60% of the medication in the blood is eliminated every 12 hours.



a.Let dₙ equal the amount of medication (in mg) in the bloodstream after n doses, where d₁ = 75.

Find a recurrence relation for dₙ.

44
views
Domanda del libro di testo

27–34. Working with sequences Several terms of a sequence {aₙ}ₙ₌₁∞ are given.

a. Find the next two terms of the sequence.


{1, 3, 9, 27, 81, ......}

48
views
Domanda del libro di testo

Explain why or why not Determine whether the following statements are true and give an explanation or counterexample.


a. A series that converges must converge absolutely.

48
views
Domanda del libro di testo

72–75. {Use of Tech} Practical sequences

Consider the following situations that generate a sequence


a.Write out the first five terms of the sequence.


Radioactive decay

A material transmutes 50% of its mass to another element every 10 years due to radioactive decay. Let Mₙ be the mass of the radioactive material at the end of the nᵗʰ decade, where the initial mass of the material is M₀ = 20g.

50
views
Domanda del libro di testo

Explain why or why not Determine whether the following statements are true and give an explanation or counterexample.


a. n!n! = (2n)! for all positive integers n.

59
views