Skip to main content
Ch. 5 - Integrals
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077당신이 사용하는 게 아니라요?교과서 변경
5장, 문제 5.PE.3a

           10           10
Suppose that Σ aₖ = -2 and Σ bₖ = 25. Find the value of
           k = 1          k = 1


  10
a. Σ aₖ/4
  k = 1

검증된 단계별 안내
1
Identify the given information: \( \sum_{k=1}^{10} a_k = -2 \) and \( \sum_{k=1}^{10} b_k = 25 \).
Understand that the problem asks for \( \sum_{k=1}^{10} \frac{a_k}{4} \), which means each term \( a_k \) is divided by 4 before summing.
Recall the property of summations that allows factoring out constants: \( \sum_{k=1}^{n} c \cdot a_k = c \cdot \sum_{k=1}^{n} a_k \), where \( c \) is a constant.
Apply this property to the given sum: \( \sum_{k=1}^{10} \frac{a_k}{4} = \frac{1}{4} \sum_{k=1}^{10} a_k \).
Substitute the known sum \( \sum_{k=1}^{10} a_k = -2 \) into the expression to write \( \sum_{k=1}^{10} \frac{a_k}{4} = \frac{1}{4} \times (-2) \).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
1m

주요 개념

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

Summation Notation (Sigma Notation)

Summation notation uses the Greek letter sigma (Σ) to represent the sum of a sequence of terms indexed by an integer variable. It concisely expresses adding terms like a₁ + a₂ + ... + aₙ. Understanding the limits of summation and the general term is essential for manipulating and evaluating sums.
추천 영상:

Properties of Summations

Summations have linearity properties, meaning the sum of a constant times a sequence equals the constant times the sum of the sequence. For example, Σ (c * aₖ) = c * Σ aₖ. This property allows factoring constants out of sums, simplifying calculations involving scaled sequences.
추천 영상:
가이드 코스
06:21
Properties of Functions

Given Series Sums and Their Use

Knowing the total sums of sequences (like Σ aₖ = -2) allows direct substitution when evaluating related sums. This is useful when the problem asks for sums of scaled or transformed sequences, enabling quick computation without summing individual terms.
추천 영상:
가이드 코스
06:45
Intro to Series: Partial Sums