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Ch. 8 - Techniques of Integration
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077당신이 사용하는 게 아니라요?교과서 변경
8장, 문제 8.3.24

Evaluate the integrals in Exercises 23–32.
∫₀^π √(1 - cos(2x)) dx

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1
Recognize that the integral involves the expression \( \sqrt{1 - \cos(2x)} \). Recall the trigonometric identity \( 1 - \cos(2x) = 2\sin^2(x) \). Use this to rewrite the integrand.
Substitute the identity into the integral to get \( \int_0^{\pi} \sqrt{2\sin^2(x)} \, dx \). Since the square root of a square is the absolute value, rewrite the integrand as \( \int_0^{\pi} \sqrt{2} |\sin(x)| \, dx \).
Consider the behavior of \( \sin(x) \) on the interval \( [0, \pi] \). Since \( \sin(x) \) is nonnegative on this interval, \( |\sin(x)| = \sin(x) \). Simplify the integral accordingly.
Factor out the constant \( \sqrt{2} \) from the integral to get \( \sqrt{2} \int_0^{\pi} \sin(x) \, dx \).
Evaluate the integral \( \int_0^{\pi} \sin(x) \, dx \) by finding the antiderivative of \( \sin(x) \), which is \( -\cos(x) \), and then apply the Fundamental Theorem of Calculus by substituting the limits \( 0 \) and \( \pi \).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
2m
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주요 개념

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

Trigonometric Identities

Trigonometric identities are equations involving trigonometric functions that hold true for all values within their domains. In this problem, the identity for cos(2x), such as cos(2x) = 1 - 2sin²(x), helps simplify the integrand √(1 - cos(2x)) into a more manageable form for integration.
추천 영상:
7:17
Verifying Trig Equations as Identities

Definite Integration

Definite integration calculates the exact area under a curve between two limits, here from 0 to π. Understanding how to evaluate integrals with specific bounds is essential to find the numerical value of the integral after simplifying the integrand.
추천 영상:
가이드 코스
05:43
Definition of the Definite Integral

Simplification of Radicals in Integrals

Simplifying expressions under a square root before integrating can make the integral easier to solve. Recognizing that √(1 - cos(2x)) can be rewritten using trigonometric identities reduces complexity and allows the use of standard integral formulas.
추천 영상:
06:13
Limits of Rational Functions with Radicals