Precalculus (6th Edition)

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

Chapter 3 - Polynomial and Rational Functions - 3.3 Zeros of Polynomial Functions - 3.3 Exercises - Page 336: 41

Answer

(a) $\pm1,\pm2,\pm3,\pm5,\pm6,\pm10,\pm15,\pm30$ (b) $\{-5,-3,2\}$ (c) $ƒ(x)=(x-2)(x+3)(x+5)$

Work Step by Step

(a) Based on the given polynomial, we have factors $p=\pm1,\pm2,\pm3,\pm5,\pm6,\pm10,\pm15,\pm30 q=\pm1$. We can list all possible rational zeros as: $\frac{p}{q}=\pm1,\pm2,\pm3,\pm5,\pm6,\pm10,\pm15,\pm30$ (b) Use synthetic division and the above possible values, find one zero $x=2$ as shown in the figure. With quotient $x^2+8x+15=0$, we have $(x+3)(x+5)=0$ which gives $x=-3, -5$. Thus the zeros are $\{-5,-3,2\}$ (c) Based on the know zeros and the factor theorem, we can factor $ƒ(x)$ into linear factors as $ƒ(x)=(x-2)(x+3)(x+5)$
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.