i need help to find the zeros, thanks in advance
in Algebra 2 Answers by

Your answer

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
To avoid this verification in future, please log in or register.

1 Answer

First find the rational zeroes. List these: -1, -2, -4, 1, 2, 4. Some of these may be actual zeroes.

We substitute each of these into the polynomial until we get two actual zeroes. It turns out that x=-2 and 2 make f(x)=0. 16+16-20-16+4=0, 16-16-20+16+4=0.

Use synthetic division to divide by -2:

-2 | 1 -2 -5  8  4

      1 -2  8 -6 -4

      1 -4  3  2  0.

Then divide this result by 2:

2 | 1 -4  3  2

     1  2 -4 -2

     1 -2 -1  0 = x²-2x-1, x²-2x+1-2=0, (x-1)²=2, x=1±√2.

Zeroes are -2, 2, 1+√2, 1-√2.

 

by Top Rated User (788k points)

Related questions

0 answers
asked Mar 15, 2013 in Algebra 2 Answers by anonymous | 191 views
0 answers
asked Apr 9, 2013 in Algebra 1 Answers by anonymous | 139 views
Welcome to MathHomeworkAnswers.org, where students, teachers and math enthusiasts can ask and answer any math question. Get help and answers to any math problem including algebra, trigonometry, geometry, calculus, trigonometry, fractions, solving expression, simplifying expressions and more. Get answers to math questions. Help is always 100% free!
85,445 questions
90,983 answers
2,192 comments
103,537 users