Solve each problem. Use Descartes' rule of signs to determine the different possibilities for the numbers of positive, negative, and nonreal complex zeros of .
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 49
Textbook Question
For each polynomial function, find all zeros and their multiplicities.
Verified step by step guidance1
Start by identifying the polynomial function given: \(f(x) = 3x(x-2)(x+3)(x^2 - 1)\).
Recognize that \(x^2 - 1\) is a difference of squares, which can be factored further as \(x^2 - 1 = (x - 1)(x + 1)\).
Rewrite the function with all factors fully factored: \(f(x) = 3x(x-2)(x+3)(x-1)(x+1)\).
List all the zeros by setting each factor equal to zero: \(x = 0\), \(x = 2\), \(x = -3\), \(x = 1\), and \(x = -1\).
Determine the multiplicity of each zero by counting how many times each factor appears in the factored form. Since each factor appears once, each zero has multiplicity 1.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Polynomial Zeros
Zeros of a polynomial are the values of x for which the function equals zero. They correspond to the roots or solutions of the polynomial equation f(x) = 0. Finding zeros involves setting each factor equal to zero and solving for x.
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Multiplicity of Zeros
Multiplicity refers to the number of times a particular zero appears as a root of the polynomial. If a factor is repeated, its zero has higher multiplicity. Multiplicity affects the graph's behavior at that zero, such as whether it crosses or just touches the x-axis.
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Factoring Polynomials
Factoring breaks down a polynomial into simpler polynomial factors. Recognizing and factoring expressions like difference of squares (x^2 - 1) helps find all zeros. Factoring is essential to identify all roots and their multiplicities accurately.
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Introduction to Factoring Polynomials
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