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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 1.25a

The unit circle has been divided into eight equal arcs, corresponding to t-values of


0, 𝜋/4, 𝜋/2, 3𝜋/4, 𝜋, 5𝜋/4, 3𝜋/2, 7𝜋/4, and 2𝜋.


a. Use the (x,y) coordinates in the figure to find the value of the trigonometric function.
b. Use periodic properties and your answer from part (a) to find the value of the same trigonometric function at the indicated real number.
<IMAGE>


sin 3𝜋/4

검증된 단계별 안내
1
Step 1: Understand the unit circle and its coordinates. The unit circle is a circle with a radius of 1 centered at the origin (0,0) in the coordinate plane. Each point on the unit circle corresponds to an angle \( t \) measured in radians from the positive x-axis.
Step 2: Identify the coordinates for \( t = \frac{3\pi}{4} \). On the unit circle, the angle \( \frac{3\pi}{4} \) is in the second quadrant. The coordinates for this angle are \( (-\frac{\sqrt{2}}{2}, \frac{\sqrt{2}}{2}) \).
Step 3: Determine the sine value. The sine of an angle \( t \) on the unit circle is the y-coordinate of the corresponding point. For \( t = \frac{3\pi}{4} \), the sine value is \( \frac{\sqrt{2}}{2} \).
Step 4: Use periodic properties to find the sine value at a different angle. The sine function is periodic with a period of \( 2\pi \). This means \( \sin(t + 2\pi k) = \sin(t) \) for any integer \( k \).
Step 5: Apply the periodic property to find the sine value at the indicated real number. If the problem specifies a different angle, use the periodic property to relate it back to \( \frac{3\pi}{4} \) and find the sine value.

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이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
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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 fundamental in trigonometry as it provides a geometric representation of the sine, cosine, and tangent functions. The coordinates of points on the unit circle correspond to the cosine and sine values of angles measured in radians, allowing for easy calculation of these trigonometric functions.
추천 영상:
06:11
Introduction to the Unit Circle

Trigonometric Functions

Trigonometric functions, such as sine and cosine, relate the angles of a triangle to the lengths of its sides. In the context of the unit circle, the sine of an angle is the y-coordinate, while the cosine is the x-coordinate of the corresponding point on the circle. Understanding these functions is crucial for solving problems involving angles and their relationships in various contexts, including periodic properties.
추천 영상:
6:04
Introduction to Trigonometric Functions

Periodic Properties

Periodic properties refer to the repeating nature of trigonometric functions. For example, the sine and cosine functions have a period of 2π, meaning their values repeat every 2π radians. This property allows us to find the values of trigonometric functions for angles greater than 2π or less than 0 by adding or subtracting multiples of 2π, which is essential for evaluating functions at various angles.
추천 영상:
5:33
Period of Sine and Cosine Functions