College Algebra 7th Edition

Published by Brooks Cole
ISBN 10: 1305115546
ISBN 13: 978-1-30511-554-5

Chapter 3, Polynomial and Rational Functions - Section 3.5 - Complex Zeros and the Fundamental Theorem of Algebra - 3.5 Exercises - Page 329: 17

Answer

a) The zeros of the function are: $\{1,-1,\frac{-1}{2}+\frac{\sqrt 3}{2}i, \frac{-1}{2}-\frac{\sqrt 3}{2}i, \frac{1}{2}+\frac{\sqrt 3}{2}i, \frac{1}{2}-\frac{\sqrt 3}{2}i\}$ b)

Work Step by Step

(a) Zeros Factor the polynomial completely to obtain: $P(x)=x^{6}-1=(x^{3}-1)(x^{3}+1)=(x-1)(x^{2}+x+1)(x+1)(x^{2}-x+1)$ $x-1=0 \rightarrow x=1$ $x+1=0 \rightarrow x=-1$ $x^{2}+x+1=0 \rightarrow x=\frac{-1}{2}\pm\frac{\sqrt 3}{2}i$ $x^{2}-x+1=0 \rightarrow x=\frac{1}{2}\pm\frac{\sqrt 3}{2}i$ Thus, the zeros of the function are: $\{1,-1,\frac{-1}{2}+\frac{\sqrt 3}{2}i, \frac{-1}{2}-\frac{\sqrt 3}{2}i, \frac{1}{2}+\frac{\sqrt 3}{2}i, \frac{1}{2}-\frac{\sqrt 3}{2}i\}$ (b) Completely Factored Form From part (a) above, the completely factored form of P(x) is: $P(x)=(x-1)(x^{2}+x+1)(x+1)(x^{2}-x+1)$
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.