Skip to main content
Ch. 8 - Integration Techniques
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243당신이 사용하는 게 아니라요?교과서 변경
8장, 문제 8.7.64

64. Using a computer algebra system, it was determined that
∫x(x+1)^8 dx = (x^10)/10 + (8x^9)/9 + (7x^8)/2 + 8x^7 + (35x^6)/3 + (56x^5)/5 + 7x^4 + (8x^3)/3 + x^2/2 + C.
Use integration by substitution to evaluate ∫x(x+1)^8 dx.

검증된 단계별 안내
1
Identify the integral to solve: \(\int x (x+1)^8 \, dx\).
Choose a substitution to simplify the integral. Let \(u = x + 1\), so that \(du = dx\) and \(x = u - 1\).
Rewrite the integral in terms of \(u\): replace \(x\) with \(u - 1\) and \(dx\) with \(du\), giving \(\int (u - 1) u^8 \, du\).
Simplify the integrand: \(\int (u^{9} - u^{8}) \, du\).
Integrate each term separately: \(\int u^{9} \, du - \int u^{8} \, du = \frac{u^{10}}{10} - \frac{u^{9}}{9} + C\). Finally, substitute back \(u = x + 1\) to express the answer in terms of \(x\).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
4m
도움이 되었나요?

주요 개념

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

Integration by Substitution

Integration by substitution is a method used to simplify integrals by changing variables. It involves choosing a substitution u = g(x) that transforms the integral into a simpler form in terms of u, making it easier to integrate. After integrating with respect to u, substitute back to the original variable x.
추천 영상:
04:27
Substitution With an Extra Variable

Chain Rule in Reverse

Integration by substitution is essentially the reverse process of the chain rule in differentiation. Recognizing the inner function and its derivative within the integrand helps identify the correct substitution. This connection allows us to rewrite the integral in a form that matches a basic integral formula.
추천 영상:
05:02
Intro to the Chain Rule

Polynomial Expansion and Integration

Understanding how to integrate polynomials term-by-term is essential after substitution or expansion. Each term of the polynomial is integrated using the power rule, which states ∫x^n dx = x^(n+1)/(n+1) + C for n ≠ -1. This knowledge helps verify the correctness of the integral obtained by substitution.
추천 영상:
07:00
Taylor Polynomials