Precalculus (10th Edition)

Published by Pearson
ISBN 10: 0-32197-907-9
ISBN 13: 978-0-32197-907-0

Chapter 9 - Polar Coordinates; Vectors - Chapter Review - Chapter Test - Page 636: 10



Work Step by Step

We know that if $z=a(\cos{\alpha}+i\sin{\alpha})$ and $w=b(\cos{\beta}+i\sin{\beta})$, then $zw=ab(\cos({\alpha+\beta)}+i\sin{(\alpha+\beta})$ and $\frac{z}{w}=\frac{a}{b}(\cos({\alpha-\beta)}+i\sin{(\alpha-\beta})$. Hence here: $zw=(2)(3)(\cos({85^\circ+22^\circ)}+i\sin{(85^\circ+22^\circ})\\zw=6(\cos({107^\circ)}+i\sin{(107^\circ}))$
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.