Precalculus (10th Edition)

Published by Pearson
ISBN 10: 0-32197-907-9
ISBN 13: 978-0-32197-907-0

Chapter 4 - Polynomial and Rational Functions - 4.5 The Real Zeros of a Polynomial Function - 4.5 Assess Your Understanding - Page 233: 59

Answer

$\{\frac{2}{3},-1\pm\sqrt 2 \}$

Work Step by Step

Step 1. Given $f(x)=3x^3+4x^2-7x+2$, list possible rational zeros as $\frac{p}{q}=\pm1,\pm2,\pm\frac{1}{3},\pm\frac{2}{3}$ Step 2. Use synthetic division as shown in the figure to find a zero $x=\frac{2}{3}$. Step 3. Use the quotient to solve $3x^2+6x-3=0$ or $x^2+2x-1=0$, thus $x=\frac{-2\pm\sqrt {4+4}}{2}=-1\pm\sqrt 2$ Step 4. Thus the real zeros are $\{\frac{2}{3},-1\pm\sqrt 2 \}$
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.