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Ch. 8 - Sequences, Induction, and Probability
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514당신이 사용하는 게 아니라요?교과서 변경
9장, 문제 43

Find the sum of each infinite geometric series. ∑i=1∞8(−0.3)i−1\(\sum\)_{i=1}^{\(\infty\)} 8(-0.3)^{i-1}

검증된 단계별 안내
1
Identify the first term \( a \) of the infinite geometric series. Since the series is given by \( \sum_{i=1}^{\infty} 8(-0.3)^{i-1} \), the first term corresponds to \( i=1 \), so \( a = 8(-0.3)^{0} = 8 \).
Determine the common ratio \( r \) of the geometric series. The common ratio is the factor by which each term is multiplied to get the next term, which is \( r = -0.3 \).
Check the condition for the sum of an infinite geometric series to exist. The sum converges only if the absolute value of the common ratio is less than 1, i.e., \( |r| < 1 \). Since \( |-0.3| = 0.3 < 1 \), the series converges.
Use the formula for the sum of an infinite geometric series: \[ S = \frac{a}{1 - r} \]. Substitute the values of \( a = 8 \) and \( r = -0.3 \) into the formula.
Simplify the expression \( \frac{8}{1 - (-0.3)} \) to find the sum of the series. This will give you the sum without calculating the final numeric value.

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주요 개념

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

Infinite Geometric Series

An infinite geometric series is the sum of infinitely many terms where each term is found by multiplying the previous term by a constant ratio. It converges only if the absolute value of the common ratio is less than 1, allowing the sum to approach a finite value.
추천 영상:
4:18
Geometric Sequences - Recursive Formula

Common Ratio

The common ratio in a geometric series is the factor by which each term is multiplied to get the next term. It is crucial for determining whether the series converges and for calculating the sum of the series when |r| < 1.
추천 영상:
5:57
Graphs of Common Functions

Sum Formula for Infinite Geometric Series

The sum of an infinite geometric series with first term a and common ratio r (where |r| < 1) is given by S = a / (1 - r). This formula allows us to find the finite sum of the series when it converges.
추천 영상:
4:18
Geometric Sequences - Recursive Formula