Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

Published by Pearson
ISBN 10: 0-32193-104-1
ISBN 13: 978-0-32193-104-7

Chapter 7 - Applications of Trigonometric Functions - Section 7.3 The Law of Cosines - 7.3 Assess Your Understanding - Page 559: 18

Answer

$b \approx1.03$ $A \approx 160.3^\circ$ $C\approx 9.7^\circ$

Work Step by Step

1. Use the Law of Cosines, we have $b=\sqrt {(2)^2+(1)^2-2(2)(1)cos10^\circ}\approx1.03$ 2. Use the Law of Sines, $\frac{sinA}{2}=\frac{sin10^\circ}{1.03}$, thus $A=sin^{-1}(\frac{2sin10^\circ}{1.03})\approx 19.7^\circ$ or $160.3^\circ$ (choose the second answer as side $a$ is the longest) 3. We have $C\approx(180-160.3-10)=9.7^\circ$
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.