/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q. 17 聽Use sum, difference, product, ... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 7: Q. 17 (page 505)

Use sum, difference, product, or half-angle formulas to find the exact value of the expression cos15掳

Short Answer

Expert verified

cos15掳=3+122

Step by step solution

01

Step 1. Rewriting the expression

We know that ,

cos(A-B) = cos(A)cos(B) +sin(A)sin(B)

15掳can be written as 45掳-30掳

So,

cos15掳=cos(45掳-30掳)cos15掳=cos45掳cos30掳+sin45掳sin30掳

02

Step 2. Calculations

cos15掳=cos45掳cos30掳+sin45掳sin30掳cos15掳=1232+1212cos15掳=3+122

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Use the fact that

cos蟺12=146+2

to findsin蟺24,cos蟺24.

Multiply and simplify:(sin(胃)+cos(胃))(sin(胃)+cos(胃))-1sin(胃)cos(胃)

In Problems 9鈥�36, find the exact value of each expression.

sincos-112

tan胃2=1-cos胃_____.

True or False:sin2胃=1-cos2胃
See all solutions

Recommended explanations on Math Textbooks

Decision Maths

Read Explanation

Geometry

Read Explanation

Applied Mathematics

Read Explanation

Discrete Mathematics

Read Explanation

Calculus

Read Explanation

Mechanics Maths

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.