Homework Help is Here – Start Your Trial Now!
Math
Trigonometry
15 a Show that cos 30 = 4 cos 0 – 3 cos 0. b By substituting x = 2 cos 0, show that the equation x Зх — 1 : = 0 has roots 2 cos 20°, -2 sin 10° and –2 cos 40°. c Use a similar approach to find, correct to three decimal places, the three real roots of the equation x3 12x = 8V3.

15 a Show that cos 30 = 4 cos 0 – 3 cos 0. b By substituting x = 2 cos 0, show that the equation x Зх — 1 : = 0 has roots 2 cos 20°, -2 sin 10° and –2 cos 40°. c Use a similar approach to find, correct to three decimal places, the three real roots of the equation x3 12x = 8V3.

Trigonometry (11th Edition)
Trigonometry (11th Edition)
11th Edition
ISBN:9780134217437
Author:Margaret L. Lial, John Hornsby, David I. Schneider, Callie Daniels
Publisher:Margaret L. Lial, John Hornsby, David I. Schneider, Callie Daniels
Chapter1: Trigonometric Functions
Section: Chapter Questions
Problem 1RE: 1. Give the measures of the complement and the supplement of an angle measuring 35°.
See similar textbooks
icon
Related questions
Question
c cosec³ 2a d v3 cosec? a + cota V3 4 cosec 2a e v3 cosec? a = 4 cot a f cot a + 3 tan a = 5 cosec a
Transcribed Image Text:c cosec³ 2a d v3 cosec? a + cota V3 4 cosec 2a e v3 cosec? a = 4 cot a f cot a + 3 tan a = 5 cosec a
15 a Show that cos 30 = 4 cos 0 – 3 cos 0. b By substituting x = 2 cos 0, show that the equation x 3x - 1 = 0 has roots 2 cos 20°, -2 sin 10° and -2 cos 40°. c Use a similar approach to find, correct to three decimal places, the three real roots of the equation x³ – 12x = 8/3.
Transcribed Image Text:15 a Show that cos 30 = 4 cos 0 – 3 cos 0. b By substituting x = 2 cos 0, show that the equation x 3x - 1 = 0 has roots 2 cos 20°, -2 sin 10° and -2 cos 40°. c Use a similar approach to find, correct to three decimal places, the three real roots of the equation x³ – 12x = 8/3.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Knowledge Booster
Solving Trigonometric Equations
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, trigonometry and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Trigonometry (11th Edition)
Trigonometry (11th Edition)
Trigonometry
ISBN:
9780134217437
Author:
Margaret L. Lial, John Hornsby, David I. Schneider, Callie Daniels
Publisher:
PEARSON
Trigonometry (MindTap Course List)
Trigonometry (MindTap Course List)
Trigonometry
ISBN:
9781305652224
Author:
Charles P. McKeague, Mark D. Turner
Publisher:
Cengage Learning
Algebra and Trigonometry
Algebra and Trigonometry
Trigonometry
ISBN:
9781938168376
Author:
Jay Abramson
Publisher:
OpenStax
Trigonometry (MindTap Course List)
Trigonometry (MindTap Course List)
Trigonometry
ISBN:
9781337278461
Author:
Ron Larson
Publisher:
Cengage Learning
SEE MORE TEXTBOOKS