Find all complex zeros of each polynomial function. Give exact values. List multiple zeros as necessary.* ƒ(x)=x4+2x3-3x2+24x-180
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- 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 113
Textbook Question
Find all complex zeros of each polynomial function. Give exact values. List multiple zeros as necessary.* ƒ(x)=x4-8x3+29x2-66x+72
Verified step by step guidance1
Start by examining the polynomial function \(f(x) = x^4 - 8x^3 + 29x^2 - 66x + 72\) to find its complex zeros. Since it is a quartic (degree 4), there will be 4 zeros in total, counting multiplicities and complex roots.
Attempt to find rational roots using the Rational Root Theorem. The possible rational roots are factors of the constant term 72 divided by factors of the leading coefficient 1, so test \(\pm1, \pm2, \pm3, \pm4, \pm6, \pm8, \pm9, \pm12, \pm18, \pm24, \pm36, \pm72\) by substituting into \(f(x)\).
Once a root \(r\) is found, use polynomial division (either synthetic or long division) to divide \(f(x)\) by \((x - r)\), reducing the quartic to a cubic polynomial.
Repeat the process of finding roots and factoring the polynomial until it is factored completely into linear and/or quadratic factors. If a quadratic factor remains that cannot be factored further over the reals, use the quadratic formula to find its complex zeros.
Write down all zeros found from the linear factors and the solutions from the quadratic formula, ensuring to express the complex zeros in exact form (using \(i\) for the imaginary unit).
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Complex Zeros of Polynomial Functions
Complex zeros are the values of x, possibly including imaginary numbers, that make the polynomial equal to zero. According to the Fundamental Theorem of Algebra, a polynomial of degree n has exactly n complex zeros, counting multiplicities. Finding these zeros involves solving the polynomial equation ƒ(x) = 0.
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Polynomial Factoring and Synthetic Division
Factoring polynomials or using synthetic division helps break down higher-degree polynomials into simpler factors. This process is essential to find zeros by reducing the polynomial to linear or quadratic factors, which can then be solved directly or by applying the quadratic formula.
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Quadratic Formula for Solving Quadratic Equations
The quadratic formula, x = (-b ± √(b² - 4ac)) / 2a, is used to find exact roots of quadratic equations. When factoring leads to quadratic factors that cannot be factored further, this formula provides the exact complex or real zeros, including those with imaginary parts.
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