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 8 - Polar Coordinates; Vectors - Section 8.3 The Complex Plane; De Moivre's Theorem - 8.3 Assess Your Understanding - Page 615: 55

Answer

$ \sqrt[4] 8(cos75^\circ+i\ sin75^\circ)$, $ \sqrt[4] 8(cos165^\circ+i\ sin165^\circ)$, $ \sqrt[4] 8(cos255^\circ+i\ sin255^\circ)$, $ \sqrt[4] 8(cos345^\circ+i\ sin345^\circ)$.

Work Step by Step

Based on the given conditions, we have: $4-4\sqrt 3i=8(cos300^\circ+i\ sin300^\circ)$, $(4-4\sqrt 3i)^{1/4}=\sqrt[4] 8(cos(\frac{360k+300}{4})^\circ+i\ sin(\frac{360k+300}{4})^\circ)$, $k=0, z_0=\sqrt[4] 8(cos75^\circ+i\ sin75^\circ)$, $k=1, z_1=\sqrt[4] 8(cos165^\circ+i\ sin165^\circ)$, $k=2, z_2=\sqrt[4] 8(cos255^\circ+i\ sin255^\circ)$, $k=3, z_3=\sqrt[4] 8(cos345^\circ+i\ sin345^\circ)$.
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.