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 47

Find a calculator approximation to four decimal places for each circular function value. cos (-0.2443)

검증된 단계별 안내
1
Recall that the cosine function is an even function, which means \(\cos(-x) = \cos(x)\). So, \(\cos(-0.2443) = \cos(0.2443)\).
Identify the angle in radians, which is \(0.2443\) radians in this case.
Use a scientific calculator or a calculator tool that can compute cosine values for angles in radians.
Input the angle \(0.2443\) into the calculator and select the cosine function to get the approximate value.
Round the result to four decimal places to obtain the final approximation for \(\cos(-0.2443)\).

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.

Circular Functions

Circular functions, such as sine and cosine, relate angles to coordinates on the unit circle. The cosine of an angle corresponds to the x-coordinate of the point on the unit circle at that angle, measured in radians. Understanding this helps interpret the function value for any given angle.
추천 영상:
5:57
Graphs of Common Functions

Angle Measurement in Radians

Angles in trigonometry are often measured in radians, where one radian equals the angle subtended by an arc equal in length to the radius of the circle. Knowing how to work with radians is essential for evaluating trigonometric functions like cosine at specific values, including negative angles.
추천 영상:
가이드 코스
5:04
Converting between Degrees & Radians

Calculator Approximation and Rounding

Calculators provide decimal approximations of trigonometric values, which often need to be rounded to a specified number of decimal places. Rounding to four decimal places means adjusting the value so that only four digits appear after the decimal point, ensuring precision and clarity in the answer.
추천 영상:
4:45
How to Use a Calculator for Trig Functions