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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 36

Find a cofunction with the same value as the given expression.
tan (𝜋/7)

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1
Recall the cofunction identity for tangent: \( \tan(\theta) = \cot\left(\frac{\pi}{2} - \theta\right) \). This means the tangent of an angle is equal to the cotangent of its complement.
Identify the given angle \( \theta = \frac{\pi}{7} \). We want to find a cofunction expression that has the same value as \( \tan\left(\frac{\pi}{7}\right) \).
Calculate the complementary angle for the cofunction by subtracting \( \theta \) from \( \frac{\pi}{2} \): \( \frac{\pi}{2} - \frac{\pi}{7} \).
Simplify the complementary angle: find a common denominator and subtract the fractions to get \( \frac{7\pi}{14} - \frac{2\pi}{14} = \frac{5\pi}{14} \).
Write the cofunction expression using the cotangent function: \( \tan\left(\frac{\pi}{7}\right) = \cot\left(\frac{5\pi}{14}\right) \).

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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.

Cofunction Identities

Cofunction identities relate trigonometric functions of complementary angles, such as sin(θ) = cos(π/2 - θ) and tan(θ) = cot(π/2 - θ). These identities allow expressing one function in terms of another evaluated at the complementary angle.
추천 영상:
6:30
Cofunction Identities

Tangent and Cotangent Relationship

Tangent and cotangent are reciprocal functions: tan(θ) = 1/cot(θ). Using cofunction identities, tan(θ) can be expressed as cot(π/2 - θ), which helps find equivalent expressions involving complementary angles.
추천 영상:
5:37
Introduction to Cotangent Graph

Radian Measure and Angle Complementarity

Angles in trigonometry are often measured in radians, where π radians equal 180 degrees. Complementary angles sum to π/2 radians (90 degrees), a key concept when applying cofunction identities to find equivalent trigonometric values.
추천 영상:
3:35
Intro to Complementary & Supplementary Angles