Skip to main content
Ch. 2 - Acute Angles and Right Triangles
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161, 9780135440780, 9780136881117, 9780135440827, 9780135924891당신이 사용하는 게 아니라요?교과서 변경
3장, 문제 2.3.27

Use a calculator to approximate the value of each expression. Give answers to six decimal places. In Exercises 21–28, simplify the expression before using the calculator. See Example 1.
1/csc(90°-51°)

검증된 단계별 안내
1
Recognize that the expression is \( \frac{1}{\csc(90^\circ - 51^\circ)} \). The first step is to simplify the angle inside the cosecant function: calculate \( 90^\circ - 51^\circ \).
Recall the co-function identity for cosecant: \( \csc(90^\circ - \theta) = \sec(\theta) \). Use this identity to rewrite \( \csc(90^\circ - 51^\circ) \) as \( \sec(51^\circ) \).
Substitute the simplified expression back into the original fraction: \( \frac{1}{\sec(51^\circ)} \).
Recall that \( \sec(\theta) = \frac{1}{\cos(\theta)} \), so \( \frac{1}{\sec(51^\circ)} = \cos(51^\circ) \).
Use a calculator to find \( \cos(51^\circ) \) and round the result to six decimal places.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
2m

주요 개념

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

Reciprocal Trigonometric Functions

The cosecant function (csc) is the reciprocal of the sine function, meaning csc(θ) = 1/sin(θ). Understanding this relationship allows simplification of expressions involving csc by converting them into sine functions, which are often easier to evaluate.
추천 영상:
6:04
Introduction to Trigonometric Functions

Co-Function Identity

The co-function identity states that csc(90° - θ) = sec(θ), linking complementary angles in trigonometry. This identity helps simplify expressions by transforming csc of a complementary angle into sec, which can then be evaluated or further simplified.
추천 영상:
6:25
Pythagorean Identities

Using a Calculator for Trigonometric Values

Calculators can approximate trigonometric values to a desired decimal precision. After simplifying the expression, input the angle in degrees or radians as required, and round the result to six decimal places for accuracy and consistency.
추천 영상:
4:45
How to Use a Calculator for Trig Functions