For each polynomial function, one zero is given. Find all other zeros.
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 52
Textbook Question
For each polynomial function, find all zeros and their multiplicities.
Verified step by step guidance1
Identify the factors of the polynomial function: \(f(x) = (2x^2 - 7x + 3)^3 (x - 2 - \sqrt{5})\). The zeros come from setting each factor equal to zero.
Find the zeros of the quadratic factor \$2x^2 - 7x + 3\( by using the quadratic formula: \)x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\(, where \)a=2\(, \)b=-7\(, and \)c=3$.
Calculate the discriminant \(\Delta = b^2 - 4ac\) to determine the nature of the roots of the quadratic. Then substitute into the quadratic formula to find the two zeros.
Note that each zero from the quadratic factor has multiplicity 3 because the entire quadratic is raised to the third power.
Find the zero from the linear factor \(x - 2 - \sqrt{5} = 0\), which gives \(x = 2 + \sqrt{5}\), and note that this zero has multiplicity 1 since the factor is to the first power.
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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 polynomial equals zero. Finding zeros involves solving the equation f(x) = 0, which may require factoring or using formulas. These zeros represent the roots or x-intercepts of the polynomial function.
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Multiplicity of Zeros
Multiplicity refers to the number of times a particular zero appears as a factor in the polynomial. If a factor is raised to a power n, the zero associated with that factor has multiplicity n. Multiplicity affects the graph's behavior at the zero, such as whether it crosses or touches the x-axis.
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Factoring and Solving Quadratic Expressions
Factoring quadratic expressions like 2x² - 7x + 3 helps find zeros by rewriting the polynomial as a product of linear factors. When factoring is difficult, the quadratic formula can be used. This step is essential to break down complex polynomials into simpler parts to identify zeros.
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