Trigonometry (10th Edition)

by Lial, Margaret L.; Hornsby, John; Schneider, David I.; Daniels, Callie

Published by Pearson

ISBN 10: 0321671775

ISBN 13: 978-0-32167-177-6

Chapter 8 - Review Exercises - Page 404: 39

Answer

The equivalent trigonometric form is $4(cos 270^\circ + i sin270^\circ)$.

Work Step by Step

$- 4i$ is at $270^\circ$ with absolute value $\sqrt{0^2 + (-4)^2} = 4$, the equivalent trigonometric form is $4(cos 270^\circ + i sin270^\circ)$.

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.