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Ch. 1 - Trigonometric Functions
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161, 9780135440780, 9780136881117, 9780135440827, 9780135924891당신이 사용하는 게 아니라요?교과서 변경
2장, 문제 8

CONCEPT PREVIEW Determine whether each statement is possible or impossible. cos θ = 1.5

검증된 단계별 안내
1
Recall the range of the cosine function: for any angle \( \theta \), \( \cos \theta \) must satisfy \( -1 \leq \cos \theta \leq 1 \).
Analyze the given value \( \cos \theta = 1.5 \) and compare it to the allowed range of cosine values.
Since \( 1.5 \) is greater than the maximum possible value of 1 for cosine, conclude that this value is outside the range of the cosine function.
Therefore, it is impossible for \( \cos \theta \) to equal 1.5 for any real angle \( \theta \).
This means the statement \( \cos \theta = 1.5 \) is impossible.

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.

Range of the Cosine Function

The cosine function outputs values only within the range of -1 to 1 for all real angles θ. Any value outside this interval, such as 1.5, is not possible for cos θ, indicating no real angle satisfies the equation.
추천 영상:
가이드 코스
4:22
Domain and Range of Function Transformations

Definition of Cosine in the Unit Circle

Cosine of an angle θ corresponds to the x-coordinate of the point on the unit circle at that angle. Since the unit circle has radius 1, the x-coordinate cannot exceed 1 or be less than -1, reinforcing the range limitation.
추천 영상:
가이드 코스
6:34
Sine, Cosine, & Tangent on the Unit Circle

Implications of Impossible Trigonometric Values

When a trigonometric equation yields a value outside the function's range, it means no real solution exists. This helps in quickly determining the feasibility of equations like cos θ = 1.5 without further calculations.
추천 영상:
가이드 코스
5:32
Fundamental Trigonometric Identities