Skip to main content
Ch. 5 - Trigonometric Identities
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161당신이 사용하는 게 아니라요?교과서 변경
6장, 문제 5.84

Verify that each equation is an identity.
(1 - cos θ)/(1 + cos θ) = 2 csc² θ - 2 csc θ cot θ - 1

검증된 단계별 안내
1
Start by expressing all trigonometric functions in terms of sine and cosine. Note that \( \csc \theta = \frac{1}{\sin \theta} \) and \( \cot \theta = \frac{\cos \theta}{\sin \theta} \).
Rewrite the right-hand side of the equation: \( 2 \csc^2 \theta - 2 \csc \theta \cot \theta - 1 \) becomes \( 2 \left(\frac{1}{\sin^2 \theta}\right) - 2 \left(\frac{1}{\sin \theta}\right)\left(\frac{\cos \theta}{\sin \theta}\right) - 1 \).
Simplify the expression: \( 2 \left(\frac{1}{\sin^2 \theta}\right) - 2 \left(\frac{\cos \theta}{\sin^2 \theta}\right) - 1 \) becomes \( \frac{2 - 2\cos \theta - \sin^2 \theta}{\sin^2 \theta} \).
Use the Pythagorean identity \( \sin^2 \theta = 1 - \cos^2 \theta \) to simplify further: \( \frac{2 - 2\cos \theta - (1 - \cos^2 \theta)}{\sin^2 \theta} \) simplifies to \( \frac{1 - \cos \theta}{1 + \cos \theta} \).
Compare the simplified right-hand side with the left-hand side \( \frac{1 - \cos \theta}{1 + \cos \theta} \) to verify that both sides are equal, confirming the identity.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
도움이 되었나요?

주요 개념

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

Trigonometric Identities

Trigonometric identities are equations that hold true for all values of the variable where both sides are defined. Common identities include the Pythagorean identities, reciprocal identities, and co-function identities. Understanding these identities is crucial for simplifying trigonometric expressions and verifying equations.
추천 영상:
5:32
Fundamental Trigonometric Identities

Cosecant and Cotangent Functions

Cosecant (csc) and cotangent (cot) are two of the six fundamental trigonometric functions. Cosecant is the reciprocal of sine (csc θ = 1/sin θ), while cotangent is the reciprocal of tangent (cot θ = cos θ/sin θ). Familiarity with these functions is essential for manipulating and transforming trigonometric equations.
추천 영상:
6:22
Graphs of Secant and Cosecant Functions

Algebraic Manipulation in Trigonometry

Algebraic manipulation involves rearranging and simplifying expressions using algebraic techniques. In trigonometry, this includes factoring, combining like terms, and applying identities to transform one side of an equation to match the other. Mastery of these skills is necessary for verifying trigonometric identities effectively.
추천 영상:
04:12
Algebraic Operations on Vectors