Answer
$4i$
Work Step by Step
Evaluate and simplify to obtain:
$4\cdot (\cos (\frac{\pi}{2})+i\cdot \sin(\frac{\pi}{2}))
\\=4(0+i\cdot 1)
\\=4(0+i)
\\=4(i)
\\=4i$
Precalculus (10th Edition)
by Sullivan, Michael
Published by
Pearson
ISBN 10:
0-32197-907-9
ISBN 13:
978-0-32197-907-0
Chapter 9 - Polar Coordinates; Vectors - 9.3 The Complex Plane; De Moivre's Theorem - 9.3 Assess Your Understanding - Page 594: 30
Update this answer!
You can help us out by revising, improving and updating this answer.
Update this answerAfter 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.
