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Ch. 10 - Sequences and Infinite Series
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243당신이 사용하는 게 아니라요?교과서 변경
10장, 문제 10.4.57

48–63. Choose your test Determine whether the following series converge or diverge using the properties and tests introduced in Sections 10.3 and 10.4.
∑ (k = 1 to ∞) (5 / 6)⁻ᵏ

검증된 단계별 안내
1
Identify the type of series given. The series is \( \sum_{k=1}^{\infty} \left( \frac{5}{6} \right)^{-k} \), which can be rewritten using properties of exponents.
Rewrite the term \( \left( \frac{5}{6} \right)^{-k} \) as \( \left( \frac{6}{5} \right)^k \) because \( a^{-k} = \frac{1}{a^k} \) and here the negative exponent flips the fraction.
Recognize that the series is now a geometric series of the form \( \sum_{k=1}^{\infty} r^k \) where \( r = \frac{6}{5} \).
Recall the convergence criterion for a geometric series: it converges if and only if \( |r| < 1 \). If \( |r| \geq 1 \), the series diverges.
Since \( r = \frac{6}{5} \) and \( \left| \frac{6}{5} \right| > 1 \), conclude that the series diverges by the geometric series test.

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이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
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2m

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Geometric Series

A geometric series is a series where each term is obtained by multiplying the previous term by a constant ratio r. It converges if the absolute value of r is less than 1, and its sum can be found using the formula S = a / (1 - r), where a is the first term.
추천 영상:
가이드 코스
06:00
Geometric Series

Convergence Tests for Series

Convergence tests help determine whether an infinite series converges or diverges. For geometric series, the key test is checking if the common ratio's absolute value is less than 1. Other tests include the nth-term test, comparison test, and ratio test, but geometric series have a straightforward criterion.
추천 영상:
가이드 코스
07:51
Choosing a Convergence Test

Properties of Exponents and Negative Powers

Understanding how to manipulate expressions with negative exponents is essential. A term like (5/6)^(-k) equals (6/5)^k, which changes the behavior of the series. Recognizing this helps correctly identify the common ratio and apply the appropriate convergence test.
추천 영상:
04:09
The Power Rule: Negative & Rational Exponents