Precalculus (6th Edition) Blitzer

Published by Pearson
ISBN 10: 0-13446-914-3
ISBN 13: 978-0-13446-914-0

Chapter 6 - Section 6.5 - Complex Numbers in Polar Form; DeMoivre's Theorem - Exercise Set - Page 767: 29


The rectangular form of the complex number is $-2-2\sqrt{3}i$.

Work Step by Step

Here $\begin{align} & z=4\left( \cos 240{}^\circ +i\sin 240{}^\circ \right) \\ & =x+iy \end{align}$ Therefore, $x=4\cos 240{}^\circ,y=4\sin 240{}^\circ $ Simplify it further to get, $\begin{align} & x=4\times \left( -\frac{1}{2} \right) \\ & =-2 \\ & y=4\times \left( -\frac{\sqrt{3}}{2} \right) \\ & =-2\sqrt{3} \end{align}$ So, the rectangular form of the complex number is $-2-2\sqrt{3}i$
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.