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Ch. 1 - Angles and the Trigonometric Functions
Blitzer - Trigonometry 3rd Edition
Blitzer3rd EditionTrigonometryISBN: 9780137316601당신이 사용하는 게 아니라요?교과서 변경
1장, 문제 1.22a

Use the unit circle shown to find the value of the trigonometric function.
sin (2𝜋/3)

검증된 단계별 안내
1
Step 1: Recognize that the angle \( \frac{2\pi}{3} \) is in radians and corresponds to 120 degrees.
Step 2: Identify the position of \( \frac{2\pi}{3} \) on the unit circle. It is in the second quadrant.
Step 3: Recall that in the second quadrant, the sine function is positive.
Step 4: Use the reference angle for \( \frac{2\pi}{3} \), which is \( \pi - \frac{2\pi}{3} = \frac{\pi}{3} \).
Step 5: The sine of \( \frac{2\pi}{3} \) is the same as the sine of its reference angle \( \frac{\pi}{3} \), which is \( \sin(\frac{\pi}{3}) \).

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

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

Unit Circle

The unit circle is a circle with a radius of one centered at the origin of a coordinate plane. It is a fundamental tool in trigonometry, as it allows for the definition of trigonometric functions based on angles measured from the positive x-axis. Each point on the unit circle corresponds to a specific angle and provides the sine and cosine values for that angle, which are essential for evaluating trigonometric functions.
추천 영상:
06:11
Introduction to the Unit Circle

Sine Function

The sine function, denoted as sin(θ), is a trigonometric function that represents the y-coordinate of a point on the unit circle corresponding to an angle θ. For angles in the second quadrant, such as 2π/3, the sine value is positive. Understanding the sine function's behavior in different quadrants is crucial for accurately determining its value for various angles.
추천 영상:
5:53
Graph of Sine and Cosine Function

Angle Measurement in Radians

In trigonometry, angles can be measured in degrees or radians, with radians being the standard unit in mathematical contexts. The angle 2π/3 radians corresponds to 120 degrees, placing it in the second quadrant of the unit circle. Recognizing how to convert between degrees and radians and understanding the implications of angle placement on the unit circle is vital for evaluating trigonometric functions.
추천 영상:
5:04
Converting between Degrees & Radians