Precalculus: Mathematics for Calculus, 7th Edition

Published by Brooks Cole
ISBN 10: 1305071751
ISBN 13: 978-1-30507-175-9

Chapter 7 - Review - Exercises - Page 579: 59

Answer

$sin(x+y)=\frac{2}{9}(\sqrt {10}+1)$

Work Step by Step

$sec~x=\frac{3}{2}$ $cos~x=\frac{1}{sec~x}=\frac{2}{3}$ $sin^2x=1-cos^2x=1-(\frac{2}{3})^2=1-\frac{4}{9}=\frac{5}{9}$ $sin~x=\frac{\sqrt 5}{3}~~$ (Quadrant I) $csc~y=3$ $sin~y=\frac{1}{csc~y}=\frac{1}{3}$ $cos^2y=1-sin^2y=1-(\frac{1}{3})^2=1-\frac{1}{9}=\frac{8}{9}$ $cos~y=\frac{2\sqrt 2}{3}~~$ (Quadrant I) Use the addition formula for sine. $sin(x+y)=sin~x~cos~y+cos~x~sin~y$ $sin(x+y)=\frac{\sqrt 5}{3}~\frac{2\sqrt 2}{3}+\frac{2}{3}\frac{1}{3}$ $sin(x+y)=\frac{2\sqrt {10}+2}{9}=\frac{2}{9}(\sqrt {10}+1)$
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.