Basic Technical Mathematics
Basic Technical Mathematics
11th Edition
ISBN: 9780134437705
Author: Washington
Publisher: PEARSON
bartleby

Concept explainers

Fundamentals of Trigonometric Identities
Trigonometric Identities are the equalities that involve trigonometry functions and hold for all the values of variables given in the equation.
bartleby

Videos

Question
Book Icon
Chapter 20.3, Problem 1PE
To determine

To evaluate: The value of cos90° by use the value for 45°.

Expert Solution & Answer
Check Mark

Want to see the full answer?

Check out a sample textbook solution
Blurred answer
Previous
Chapter 20.2, Problem 54E
Next
Chapter 20.3, Problem 2PE

Chapter 20 Solutions

Basic Technical Mathematics

Ch. 20.1 - Prob. 1PECh. 20.1 - Prob. 2PECh. 20.1 - Prob. 3PECh. 20.1 - Prob. 1ECh. 20.1 - Prob. 2ECh. 20.1 - In Exercises 36, use a calculator to check the...Ch. 20.1 - Prob. 4ECh. 20.1 - Prob. 5ECh. 20.1 - Prob. 6ECh. 20.1 - Prob. 7E
Ch. 20.1 - Prob. 8ECh. 20.1 - Prob. 9ECh. 20.1 - Prob. 10ECh. 20.1 - Prob. 11ECh. 20.1 - Prob. 12ECh. 20.1 - Prob. 13ECh. 20.1 - Prob. 14ECh. 20.1 - Prob. 15ECh. 20.1 - Prob. 16ECh. 20.1 - Prob. 17ECh. 20.1 - Prob. 18ECh. 20.1 - In Exercises 19–38, prove the given identities. Ch. 20.1 - Prob. 20ECh. 20.1 - In Exercises 19–38, prove the given identities. Ch. 20.1 - Prob. 22ECh. 20.1 - Prob. 23ECh. 20.1 - Prob. 24ECh. 20.1 - Prob. 25ECh. 20.1 - Prob. 26ECh. 20.1 - Prob. 27ECh. 20.1 - Prob. 28ECh. 20.1 - Prob. 29ECh. 20.1 - Prob. 30ECh. 20.1 - Prob. 31ECh. 20.1 - Prob. 32ECh. 20.1 - Prob. 33ECh. 20.1 - Prob. 34ECh. 20.1 - Prob. 35ECh. 20.1 - Prob. 36ECh. 20.1 - Prob. 37ECh. 20.1 - Prob. 38ECh. 20.1 - Prob. 39ECh. 20.1 - Prob. 40ECh. 20.1 - Prob. 41ECh. 20.1 - Prob. 42ECh. 20.1 - Prob. 43ECh. 20.1 - Prob. 44ECh. 20.1 - Prob. 45ECh. 20.1 - Prob. 46ECh. 20.1 - Prob. 47ECh. 20.1 - Prob. 48ECh. 20.1 - In Exercises 47–50, for a first-quadrant angle,...Ch. 20.1 - Prob. 50ECh. 20.1 - Prob. 51ECh. 20.1 - Prob. 52ECh. 20.1 - Prob. 53ECh. 20.1 - Prob. 54ECh. 20.1 - Prob. 55ECh. 20.1 - Prob. 56ECh. 20.1 - Prob. 57ECh. 20.1 - Prob. 58ECh. 20.1 - Prob. 59ECh. 20.1 - Prob. 60ECh. 20.1 - Prob. 61ECh. 20.1 - Prob. 62ECh. 20.1 - Prob. 63ECh. 20.1 - In Exercise 63–70, solve the given...Ch. 20.1 - Prob. 65ECh. 20.1 - Prob. 66ECh. 20.1 - Prob. 67ECh. 20.1 - Prob. 68ECh. 20.1 - Prob. 69ECh. 20.1 - Prob. 70ECh. 20.1 - Prob. 71ECh. 20.1 - Prob. 72ECh. 20.1 - Prob. 73ECh. 20.1 - Prob. 74ECh. 20.2 - Prob. 1PECh. 20.2 - Prob. 2PECh. 20.2 - Prob. 1ECh. 20.2 - In Exercises 1 and 2, make the given changes in...Ch. 20.2 - Prob. 3ECh. 20.2 - In Exercises 36, determine the values of the given...Ch. 20.2 - Prob. 5ECh. 20.2 - Prob. 6ECh. 20.2 - Prob. 7ECh. 20.2 - Prob. 8ECh. 20.2 - Prob. 9ECh. 20.2 - Prob. 10ECh. 20.2 - Prob. 11ECh. 20.2 - In Exercises 1120, simplify the given...Ch. 20.2 - Prob. 13ECh. 20.2 - Prob. 14ECh. 20.2 - Prob. 15ECh. 20.2 - Prob. 16ECh. 20.2 - Prob. 17ECh. 20.2 - Prob. 18ECh. 20.2 - Prob. 19ECh. 20.2 - Prob. 20ECh. 20.2 - In Exercises 2124, evaluate each expression by...Ch. 20.2 - In Exercises 21–24, evaluate each expression by...Ch. 20.2 - Prob. 23ECh. 20.2 - Prob. 24ECh. 20.2 - Prob. 25ECh. 20.2 - Prob. 26ECh. 20.2 - Prob. 27ECh. 20.2 - Prob. 28ECh. 20.2 - Prob. 29ECh. 20.2 - Prob. 30ECh. 20.2 - Prob. 31ECh. 20.2 - Prob. 32ECh. 20.2 - Prob. 33ECh. 20.2 - Prob. 34ECh. 20.2 - Prob. 35ECh. 20.2 - Prob. 36ECh. 20.2 - Prob. 37ECh. 20.2 - Prob. 38ECh. 20.2 - Prob. 39ECh. 20.2 - Prob. 40ECh. 20.2 - Prob. 41ECh. 20.2 - In Exercises 4154, solve the given...Ch. 20.2 - Prob. 43ECh. 20.2 - Prob. 44ECh. 20.2 - Prob. 45ECh. 20.2 - Prob. 46ECh. 20.2 - Prob. 47ECh. 20.2 - Prob. 48ECh. 20.2 - Prob. 49ECh. 20.2 - Prob. 50ECh. 20.2 - Prob. 51ECh. 20.2 - Prob. 52ECh. 20.2 - Prob. 53ECh. 20.2 - Prob. 54ECh. 20.3 - Evaluate cos 90° using values for 45°. Ch. 20.3 - Simplify: Ch. 20.3 - In Exercises 1–4, make the given changes in the...Ch. 20.3 - In Exercises 1–4, make the given changes in the...Ch. 20.3 - In Exercises 1–4, make the given changes in the...Ch. 20.3 - Prob. 4ECh. 20.3 - Prob. 5ECh. 20.3 - In Exercises 5–8, determine the values of the...Ch. 20.3 - Prob. 7ECh. 20.3 - Prob. 8ECh. 20.3 - Prob. 9ECh. 20.3 - Prob. 10ECh. 20.3 - Prob. 11ECh. 20.3 - In Exercises 9–14, use a calculator to verify the...Ch. 20.3 - Prob. 13ECh. 20.3 - Prob. 14ECh. 20.3 - Prob. 15ECh. 20.3 - Prob. 16ECh. 20.3 - Prob. 17ECh. 20.3 - Prob. 18ECh. 20.3 - Prob. 19ECh. 20.3 - In Exercises 19–30, simplify the given...Ch. 20.3 - In Exercises 19–30, simplify the given...Ch. 20.3 - Prob. 22ECh. 20.3 - Prob. 23ECh. 20.3 - Prob. 24ECh. 20.3 - Prob. 25ECh. 20.3 - Prob. 26ECh. 20.3 - Prob. 27ECh. 20.3 - Prob. 28ECh. 20.3 - Prob. 29ECh. 20.3 - Prob. 30ECh. 20.3 - Prob. 31ECh. 20.3 - Prob. 32ECh. 20.3 - Prob. 33ECh. 20.3 - Prob. 34ECh. 20.3 - Prob. 35ECh. 20.3 - Prob. 36ECh. 20.3 - Prob. 37ECh. 20.3 - Prob. 38ECh. 20.3 - Prob. 39ECh. 20.3 - Prob. 40ECh. 20.3 - Prob. 41ECh. 20.3 - Prob. 42ECh. 20.3 - Prob. 43ECh. 20.3 - Prob. 44ECh. 20.3 - Prob. 45ECh. 20.3 - Prob. 46ECh. 20.3 - Prob. 47ECh. 20.3 - Prob. 48ECh. 20.3 - Prob. 49ECh. 20.3 - Prob. 50ECh. 20.3 - Prob. 51ECh. 20.3 - Prob. 52ECh. 20.3 - Prob. 53ECh. 20.3 - Prob. 54ECh. 20.3 - Prob. 55ECh. 20.3 - Prob. 56ECh. 20.3 - Prob. 57ECh. 20.3 - Prob. 58ECh. 20.3 - Prob. 59ECh. 20.3 - Prob. 60ECh. 20.3 - Prob. 61ECh. 20.3 - Prob. 62ECh. 20.4 - Prob. 1PECh. 20.4 - Prob. 1ECh. 20.4 - Prob. 3ECh. 20.4 - Prob. 4ECh. 20.4 - Prob. 5ECh. 20.4 - Prob. 6ECh. 20.4 - Prob. 7ECh. 20.4 - Prob. 8ECh. 20.4 - Prob. 9ECh. 20.4 - Prob. 10ECh. 20.4 - Prob. 11ECh. 20.4 - Prob. 12ECh. 20.4 - Prob. 13ECh. 20.4 - Prob. 14ECh. 20.4 - Prob. 15ECh. 20.4 - Prob. 16ECh. 20.4 - Prob. 17ECh. 20.4 - Prob. 18ECh. 20.4 - Prob. 19ECh. 20.4 - Prob. 20ECh. 20.4 - Prob. 21ECh. 20.4 - In Exercises 21–24, evaluate the indicated...Ch. 20.4 - Prob. 23ECh. 20.4 - Prob. 24ECh. 20.4 - In Exercises 25–28, derive the required...Ch. 20.4 - Prob. 26ECh. 20.4 - Prob. 27ECh. 20.4 - Prob. 28ECh. 20.4 - Prob. 29ECh. 20.4 - Prob. 30ECh. 20.4 - Prob. 31ECh. 20.4 - Prob. 32ECh. 20.4 - Prob. 33ECh. 20.4 - Prob. 34ECh. 20.4 - Prob. 35ECh. 20.4 - Prob. 36ECh. 20.4 - Prob. 37ECh. 20.4 - Prob. 38ECh. 20.4 - Prob. 39ECh. 20.4 - Prob. 40ECh. 20.4 - Prob. 41ECh. 20.4 - Prob. 42ECh. 20.4 - Prob. 43ECh. 20.4 - Prob. 44ECh. 20.4 - Prob. 45ECh. 20.4 - Prob. 46ECh. 20.4 - Prob. 47ECh. 20.4 - Prob. 48ECh. 20.5 - Prob. 1PECh. 20.5 - Prob. 2PECh. 20.5 - Prob. 1ECh. 20.5 - Prob. 2ECh. 20.5 - Prob. 3ECh. 20.5 - Prob. 4ECh. 20.5 - Prob. 5ECh. 20.5 - In Exercises 5–20, solve the given trigonometric...Ch. 20.5 - Prob. 7ECh. 20.5 - In Exercises 5–20, solve the given trigonometric...Ch. 20.5 - Prob. 9ECh. 20.5 - Prob. 10ECh. 20.5 - Prob. 11ECh. 20.5 - Prob. 12ECh. 20.5 - Prob. 13ECh. 20.5 - Prob. 14ECh. 20.5 - Prob. 15ECh. 20.5 - In Exercises 5–20, solve the given trigonometric...Ch. 20.5 - Prob. 17ECh. 20.5 - Prob. 18ECh. 20.5 - Prob. 19ECh. 20.5 - Prob. 20ECh. 20.5 - Prob. 21ECh. 20.5 - Prob. 22ECh. 20.5 - Prob. 23ECh. 20.5 - Prob. 24ECh. 20.5 - Prob. 25ECh. 20.5 - Prob. 26ECh. 20.5 - Prob. 27ECh. 20.5 - Prob. 28ECh. 20.5 - Prob. 29ECh. 20.5 - Prob. 30ECh. 20.5 - Prob. 31ECh. 20.5 - Prob. 32ECh. 20.5 - Prob. 33ECh. 20.5 - Prob. 34ECh. 20.5 - Prob. 35ECh. 20.5 - Prob. 36ECh. 20.5 - Prob. 37ECh. 20.5 - Prob. 38ECh. 20.5 - Prob. 39ECh. 20.5 - Prob. 40ECh. 20.5 - Prob. 41ECh. 20.5 - Prob. 42ECh. 20.5 - Prob. 43ECh. 20.5 - Prob. 44ECh. 20.5 - Prob. 45ECh. 20.5 - Prob. 46ECh. 20.5 - Prob. 47ECh. 20.5 - Prob. 48ECh. 20.5 - Prob. 49ECh. 20.5 - Prob. 50ECh. 20.5 - Prob. 51ECh. 20.5 - Prob. 52ECh. 20.5 - Prob. 53ECh. 20.5 - Prob. 54ECh. 20.5 - Prob. 55ECh. 20.5 - Prob. 56ECh. 20.5 - Prob. 57ECh. 20.5 - Prob. 58ECh. 20.5 - Prob. 59ECh. 20.5 - Prob. 60ECh. 20.5 - Prob. 61ECh. 20.5 - Prob. 62ECh. 20.6 - Prob. 1PECh. 20.6 - Prob. 2PECh. 20.6 - Prob. 1ECh. 20.6 - Prob. 2ECh. 20.6 - Prob. 3ECh. 20.6 - Prob. 4ECh. 20.6 - Prob. 5ECh. 20.6 - Prob. 6ECh. 20.6 - Prob. 7ECh. 20.6 - Prob. 8ECh. 20.6 - Prob. 9ECh. 20.6 - Prob. 10ECh. 20.6 - Prob. 11ECh. 20.6 - In Exercises 11—28, evaluate exactly the given...Ch. 20.6 - In Exercises 11—28, evaluate exactly the given...Ch. 20.6 - In Exercises 11—28, evaluate exactly the given...Ch. 20.6 - Prob. 15ECh. 20.6 - Prob. 16ECh. 20.6 - Prob. 17ECh. 20.6 - In Exercises 11—28, evaluate exactly the given...Ch. 20.6 - Prob. 19ECh. 20.6 - Prob. 20ECh. 20.6 - Prob. 21ECh. 20.6 - Prob. 22ECh. 20.6 - Prob. 23ECh. 20.6 - Prob. 24ECh. 20.6 - Prob. 25ECh. 20.6 - Prob. 26ECh. 20.6 - Prob. 27ECh. 20.6 - Prob. 28ECh. 20.6 - Prob. 29ECh. 20.6 - Prob. 30ECh. 20.6 - Prob. 31ECh. 20.6 - Prob. 32ECh. 20.6 - In Exercises 29—36, use a calculator to evaluate...Ch. 20.6 - In Exercises 29—36, use a calculator to evaluate...Ch. 20.6 - Prob. 35ECh. 20.6 - In Exercises 29—36, use a calculator to evaluate...Ch. 20.6 - Prob. 37ECh. 20.6 - Prob. 38ECh. 20.6 - Prob. 39ECh. 20.6 - Prob. 40ECh. 20.6 - Prob. 41ECh. 20.6 - Prob. 42ECh. 20.6 - Prob. 43ECh. 20.6 - Prob. 44ECh. 20.6 - Prob. 45ECh. 20.6 - Prob. 46ECh. 20.6 - Prob. 47ECh. 20.6 - Prob. 48ECh. 20.6 - Prob. 49ECh. 20.6 - Prob. 50ECh. 20.6 - In Exercises 51–56, solve the given problems with...Ch. 20.6 - Prob. 52ECh. 20.6 - Prob. 53ECh. 20.6 - Prob. 54ECh. 20.6 - Prob. 55ECh. 20.6 - Prob. 56ECh. 20.6 - Prob. 57ECh. 20.6 - Prob. 58ECh. 20.6 - Prob. 59ECh. 20.6 - Prob. 60ECh. 20.6 - Prob. 61ECh. 20.6 - Prob. 62ECh. 20.6 - Prob. 63ECh. 20.6 - Prob. 64ECh. 20.6 - Prob. 65ECh. 20.6 - Prob. 66ECh. 20.6 - Prob. 67ECh. 20.6 - Prob. 68ECh. 20.6 - Prob. 69ECh. 20.6 - Prob. 70ECh. 20.6 - Prob. 71ECh. 20.6 - Prob. 72ECh. 20.6 - Prob. 73ECh. 20.6 - Prob. 74ECh. 20.6 - Prob. 75ECh. 20.6 - Prob. 76ECh. 20 - Prob. 1RECh. 20 - Prob. 2RECh. 20 - Prob. 3RECh. 20 - Prob. 4RECh. 20 - Prob. 5RECh. 20 - Prob. 6RECh. 20 - Prob. 7RECh. 20 - Prob. 8RECh. 20 - Prob. 9RECh. 20 - Prob. 10RECh. 20 - Prob. 11RECh. 20 - Prob. 12RECh. 20 - Prob. 13RECh. 20 - Prob. 14RECh. 20 - In Exercises 15–22, simplify the given expressions...Ch. 20 - In Exercises 15–22, simplify the given expressions...Ch. 20 - Prob. 17RECh. 20 - Prob. 18RECh. 20 - Prob. 19RECh. 20 - Prob. 20RECh. 20 - Prob. 21RECh. 20 - Prob. 22RECh. 20 - Prob. 23RECh. 20 - Prob. 24RECh. 20 - Prob. 25RECh. 20 - Prob. 26RECh. 20 - Prob. 27RECh. 20 - Prob. 28RECh. 20 - Prob. 29RECh. 20 - Prob. 30RECh. 20 - Prob. 31RECh. 20 - Prob. 32RECh. 20 - Prob. 33RECh. 20 - Prob. 34RECh. 20 - Prob. 35RECh. 20 - Prob. 36RECh. 20 - Prob. 37RECh. 20 - Prob. 38RECh. 20 - Prob. 39RECh. 20 - Prob. 40RECh. 20 - Prob. 41RECh. 20 - Prob. 42RECh. 20 - Prob. 43RECh. 20 - Prob. 44RECh. 20 - Prob. 45RECh. 20 - Prob. 46RECh. 20 - Prob. 47RECh. 20 - Prob. 48RECh. 20 - Prob. 50RECh. 20 - Prob. 51RECh. 20 - Prob. 52RECh. 20 - Prob. 53RECh. 20 - Prob. 54RECh. 20 - In Exercises 51—58, simplify the given...Ch. 20 - Prob. 56RECh. 20 - Prob. 57RECh. 20 - Prob. 58RECh. 20 - Prob. 59RECh. 20 - Prob. 60RECh. 20 - Prob. 61RECh. 20 - Prob. 62RECh. 20 - Prob. 63RECh. 20 - Prob. 64RECh. 20 - Prob. 65RECh. 20 - Prob. 66RECh. 20 - Prob. 67RECh. 20 - Prob. 68RECh. 20 - Prob. 69RECh. 20 - Prob. 70RECh. 20 - Prob. 71RECh. 20 - Prob. 72RECh. 20 - Prob. 73RECh. 20 - Prob. 74RECh. 20 - Prob. 75RECh. 20 - Prob. 76RECh. 20 - Prob. 77RECh. 20 - Prob. 78RECh. 20 - Prob. 79RECh. 20 - Prob. 80RECh. 20 - Prob. 81RECh. 20 - Prob. 82RECh. 20 - Prob. 83RECh. 20 - Prob. 84RECh. 20 - Prob. 85RECh. 20 - Prob. 86RECh. 20 - Prob. 87RECh. 20 - Prob. 88RECh. 20 - Prob. 89RECh. 20 - Prob. 90RECh. 20 - Prob. 91RECh. 20 - Prob. 92RECh. 20 - Prob. 93RECh. 20 - Prob. 94RECh. 20 - Prob. 95RECh. 20 - Prob. 96RECh. 20 - Prob. 97RECh. 20 - Prob. 98RECh. 20 - Prob. 99RECh. 20 - Prob. 100RECh. 20 - Prob. 101RECh. 20 - Prob. 102RECh. 20 - Prob. 103RECh. 20 - Prob. 104RECh. 20 - Prob. 105RECh. 20 - Prob. 106RECh. 20 - Prob. 107RECh. 20 - Prob. 108RECh. 20 - Prob. 109RECh. 20 - Prob. 110RECh. 20 - Prob. 111RECh. 20 - Prob. 112RECh. 20 - Prob. 113RECh. 20 - Prob. 114RECh. 20 - Prob. 115RECh. 20 - Prob. 116RECh. 20 - Prob. 117RECh. 20 - Prob. 118RECh. 20 - Prob. 119RECh. 20 - Prob. 120RECh. 20 - Prob. 121RECh. 20 - Prob. 122RECh. 20 - Prob. 123RECh. 20 - Prob. 124RECh. 20 - Prob. 125RECh. 20 - Prob. 126RECh. 20 - Prob. 127RECh. 20 - Prob. 128RECh. 20 - Prob. 129RECh. 20 - Prob. 130RECh. 20 - Prob. 131RECh. 20 - Prob. 1PTCh. 20 - Prob. 2PTCh. 20 - Prob. 3PTCh. 20 - Prob. 4PTCh. 20 - Prob. 5PTCh. 20 - Prob. 6PTCh. 20 - Prob. 7PTCh. 20 - Prob. 8PTCh. 20 - Prob. 9PTCh. 20 - Prob. 10PT
Knowledge Booster
Background pattern image
Math
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, subject and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Text book image
Discrete Mathematics and Its Applications ( 8th I...
Math
ISBN:9781259676512
Author:Kenneth H Rosen
Publisher:McGraw-Hill Education
Text book image
Mathematics for Elementary Teachers with Activiti...
Math
ISBN:9780134392790
Author:Beckmann, Sybilla
Publisher:PEARSON
Text book image
Calculus Volume 1
Math
ISBN:9781938168024
Author:Strang, Gilbert
Publisher:OpenStax College
Text book image
Thinking Mathematically (7th Edition)
Math
ISBN:9780134683713
Author:Robert F. Blitzer
Publisher:PEARSON
Text book image
Discrete Mathematics With Applications
Math
ISBN:9781337694193
Author:EPP, Susanna S.
Publisher:Cengage Learning,
Text book image
Pathways To Math Literacy (looseleaf)
Math
ISBN:9781259985607
Author:David Sobecki Professor, Brian A. Mercer
Publisher:McGraw-Hill Education
SEE MORE TEXTBOOKS
Fundamental Trigonometric Identities: Reciprocal, Quotient, and Pythagorean Identities; Author: Mathispower4u;https://www.youtube.com/watch?v=OmJ5fxyXrfg;License: Standard YouTube License, CC-BY