In Exercises 1–8, use the Rational Zero Theorem to list all possible rational zeros for each given function. f(x)=x3+x2−4x−4
Table of contents
- 0. Review of Algebra4h 18m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations1h 43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 5m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 22m
- 10. Combinatorics & Probability1h 45m
4. Polynomial Functions
Zeros of Polynomial Functions
Problem 14
Textbook Question
In Exercises 9–16, a) List all possible rational zeros. b) Use synthetic division to test the possible rational zeros and find an actual zero. c) Use the quotient from part (b) to find the remaining zeros of the polynomial function. f(x)=2x3+x2−3x+1
Verified step by step guidance1
Identify the polynomial function: .
List all possible rational zeros using the Rational Root Theorem. The possible rational zeros are of the form , where divides the constant term (1) and divides the leading coefficient (2). So, possible rational zeros are .
Use synthetic division to test each possible rational zero. Start by testing : set up synthetic division with coefficients and divide by . Check the remainder to see if it is zero, indicating a root.
Once you find a zero (say ), use the quotient polynomial from the synthetic division (which will be a quadratic) to find the remaining zeros.
Solve the quadratic quotient either by factoring, completing the square, or using the quadratic formula to find the remaining zeros of the polynomial.
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
5mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Rational Root Theorem
The Rational Root Theorem helps identify all possible rational zeros of a polynomial by considering factors of the constant term and the leading coefficient. These possible roots are expressed as ±(factors of constant term)/(factors of leading coefficient), providing a finite list to test.
Recommended video:
Guided course
Rational Exponents
Synthetic Division
Synthetic division is a streamlined method for dividing a polynomial by a binomial of the form (x - c). It simplifies calculations to test whether a candidate root is an actual zero by checking if the remainder is zero, and it produces a quotient polynomial for further analysis.
Recommended video:
Higher Powers of i
Factoring Polynomials and Finding Zeros
Once a zero is found using synthetic division, the quotient polynomial can be factored further or solved using other methods to find remaining zeros. This step breaks down the polynomial into simpler factors, revealing all roots including real and complex zeros.
Recommended video:
Guided course
Introduction to Factoring Polynomials
Related Videos
Related Practice
Textbook Question
508
views
