Skip to main content
Ch. 5 - Trigonometric Identities
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161당신이 사용하는 게 아니라요?교과서 변경
6장, 문제 5.56

Verify that each equation is an identity.
sec⁴ x - sec² x = tan⁴ x + tan² x

검증된 단계별 안내
1
Start by recalling the Pythagorean identity: \( \sec^2 x = 1 + \tan^2 x \).
Substitute \( \sec^2 x = 1 + \tan^2 x \) into the left side of the equation: \( \sec^4 x - \sec^2 x \).
Rewrite \( \sec^4 x \) as \( (\sec^2 x)^2 \) and substitute \( \sec^2 x = 1 + \tan^2 x \) to get \( ((1 + \tan^2 x)^2) - (1 + \tan^2 x) \).
Expand \( (1 + \tan^2 x)^2 \) to \( 1 + 2\tan^2 x + \tan^4 x \) and simplify the expression: \( 1 + 2\tan^2 x + \tan^4 x - 1 - \tan^2 x \).
Combine like terms to verify the identity: \( \tan^4 x + \tan^2 x \).

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 quotient identities. Understanding these identities is crucial for verifying equations and simplifying expressions in trigonometry.
추천 영상:
5:32
Fundamental Trigonometric Identities

Secant and Tangent Functions

The secant function, sec(x), is defined as the reciprocal of the cosine function, while the tangent function, tan(x), is the ratio of the sine function to the cosine function. These functions are fundamental in trigonometry and are often used in identities and equations. Recognizing their relationships helps in manipulating and verifying trigonometric equations.
추천 영상:
6:22
Graphs of Secant and Cosecant Functions

Algebraic Manipulation

Algebraic manipulation involves rearranging and simplifying equations using algebraic rules. This includes factoring, expanding, and combining like terms. In the context of verifying trigonometric identities, effective algebraic manipulation allows one to transform one side of the equation to match the other, confirming the identity.
추천 영상:
04:12
Algebraic Operations on Vectors