Precalculus (6th Edition)

Published by Pearson
ISBN 10: 013421742X
ISBN 13: 978-0-13421-742-0

Chapter 1 - Equations and Inequalities - 1.3 Complex Numbers - 1.3 Exercises - Page 111: 28

Answer

$-4i\sqrt5$

Work Step by Step

Factor the radicand so that one factor is a perfect square then simplify to obtain: $=-\sqrt{16(-5)} \\=-\sqrt{4^2(-5)} \\=-4\sqrt{-4}$ Factor out $-1$ in the radicand to obtain: $=-4\sqrt{-1(5)}$ Since $\sqrt{-1} = i$, bring out the square root of $-1$, which is $i$, to obtain: $=-4i\sqrt5$
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.