Skip to main content
Ch. 8 - Techniques of Integration
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077당신이 사용하는 게 아니라요?교과서 변경
8장, 문제 8.4.32

Use any method to evaluate the integrals in Exercises 15–38. Most will require trigonometric substitutions, but some can be evaluated by other methods.
∫ (1 - x²)^(1/2) / x⁴ dx

검증된 단계별 안내
1
Identify the integral to solve: \(\int \frac{\sqrt{1 - x^{2}}}{x^{4}} \, dx\).
Recognize that the integrand contains \(\sqrt{1 - x^{2}}\), which suggests a trigonometric substitution using \(x = \sin \theta\) because \(1 - \sin^{2} \theta = \cos^{2} \theta\).
Make the substitution \(x = \sin \theta\), then compute \(dx = \cos \theta \, d\theta\). Rewrite the integral in terms of \(\theta\):
\[\int \frac{\sqrt{1 - \sin^{2} \theta}}{\sin^{4} \theta} \cdot \cos \theta \, d\theta = \int \frac{\cos \theta}{\sin^{4} \theta} \cdot \cos \theta \, d\theta = \int \frac{\cos^{2} \theta}{\sin^{4} \theta} \, d\theta.\]
Simplify the integral to \(\int \frac{\cos^{2} \theta}{\sin^{4} \theta} \, d\theta\). Use the identity \(\cos^{2} \theta = 1 - \sin^{2} \theta\) to rewrite the numerator if needed, and express the integral in terms of powers of \(\sin \theta\) to facilitate integration.
After integrating with respect to \(\theta\), substitute back \(\theta = \arcsin x\) 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:
12m
도움이 되었나요?

주요 개념

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

Trigonometric Substitution

Trigonometric substitution is a technique used to evaluate integrals involving expressions like √(a² - x²), √(x² + a²), or √(x² - a²). By substituting x with a trigonometric function (e.g., x = a sin θ), the integral is transformed into a trigonometric integral that is often easier to solve.
추천 영상:
가이드 코스
6:04
Introduction to Trigonometric Functions

Integration of Rational Functions

Integration of rational functions involves integrating expressions where the integrand is a ratio of polynomials. Recognizing when to simplify or rewrite the integrand, such as expressing powers of x in the denominator, helps in applying substitution or partial fractions to evaluate the integral.
추천 영상:
6:04
Intro to Rational Functions

Simplifying Radicals in Integrals

Simplifying radicals like √(1 - x²) is essential before integration. This often involves rewriting the expression using trigonometric identities or algebraic manipulation to make the integral more manageable, especially when combined with powers of x in the denominator.
추천 영상:
06:13
Limits of Rational Functions with Radicals