Skip to main content
Ch. 3 - Radian Measure and The Unit Circle
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161당신이 사용하는 게 아니라요?교과서 변경
4장, 문제 71

Find the exact value of s in the given interval that has the given circular function value.


[3π/2, 2π] ; tan s = -1

검증된 단계별 안내
1
Identify the given interval for the variable \(s\), which is \(\left[\frac{3\pi}{2}, 2\pi\right]\), and the equation \(\tan s = -1\).
Recall that the tangent function has a period of \(\pi\), meaning \(\tan(s) = \tan(s + k\pi)\) for any integer \(k\). Also, tangent is negative in the second and fourth quadrants.
Determine the reference angle where \(\tan \theta = 1\). Since \(\tan s = -1\), the angle \(s\) must correspond to an angle where the tangent is \(1\) but with a negative sign.
Find the angles in the interval \(\left[\frac{3\pi}{2}, 2\pi\right]\) where \(\tan s = -1\). This interval corresponds to the fourth quadrant, where tangent is negative.
Express the solution(s) for \(s\) in terms of \(\pi\) using the reference angle \(\frac{\pi}{4}\), and verify that the solution(s) lie within the given interval.

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.

Unit Circle and Angle Intervals

The unit circle represents angles and their corresponding trigonometric values on a circle of radius 1. Understanding the interval [3π/2, 2π] means focusing on angles in the fourth quadrant, where the angle measures range from 270° to 360°, which affects the sign and value of trigonometric functions.
추천 영상:
06:11
Introduction to the Unit Circle

Tangent Function and Its Values

The tangent of an angle is the ratio of the sine to the cosine of that angle (tan θ = sin θ / cos θ). Knowing that tan s = -1 means the sine and cosine values have equal magnitude but opposite signs, which helps identify specific reference angles where this condition holds.
추천 영상:
5:08
Sine, Cosine, & Tangent of 30°, 45°, & 60°

Reference Angles and Sign of Trigonometric Functions

Reference angles are acute angles used to determine trigonometric values in different quadrants. Since tangent is negative in the fourth quadrant, the solution for s must correspond to an angle whose reference angle has tan = 1, but with a negative sign, guiding the exact value within the given interval.
추천 영상:
5:31
Reference Angles on the Unit Circle