Table of contents
- 0. Review of Algebra4h 16m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 6m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 19m
- 10. Combinatorics & Probability1h 45m
4. Polynomial Functions
Zeros of Polynomial Functions
Problem 19a
Textbook Question
In Exercises 17–24, a) List all possible rational roots. b) List all possible rational roots. c) Use the quotient from part (b) to find the remaining roots and solve the equation. x^3−10x−12=0
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1
Step 1: Identify the polynomial equation given: \(x^3 - 10x - 12 = 0\).
Step 2: Use the Rational Root Theorem to list all possible rational roots. The possible rational roots are the factors of the constant term (-12) divided by the factors of the leading coefficient (1).
Step 3: List the factors of -12: \(\pm 1, \pm 2, \pm 3, \pm 4, \pm 6, \pm 12\). Since the leading coefficient is 1, the possible rational roots are \(\pm 1, \pm 2, \pm 3, \pm 4, \pm 6, \pm 12\).
Step 4: Use synthetic division or polynomial division to test these possible rational roots and find one actual root of the equation.
Step 5: Once a root is found, use the quotient from the division to factor the polynomial further and find the remaining roots.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Rational Root Theorem
The Rational Root Theorem states that any rational solution of a polynomial equation, in the form of p/q, must have p as a factor of the constant term and q as a factor of the leading coefficient. This theorem helps in identifying all possible rational roots of a polynomial, which can then be tested to find actual roots.
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Synthetic Division
Synthetic division is a simplified form of polynomial long division that allows for the division of a polynomial by a linear factor. It is particularly useful for finding the quotient and remainder when a polynomial is divided by a binomial of the form (x - r), where r is a root. This method streamlines the process of finding remaining roots after identifying one root.
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Factoring Polynomials
Factoring polynomials involves expressing a polynomial as a product of its factors, which can be linear or quadratic expressions. Once a polynomial is factored, it becomes easier to solve for its roots by setting each factor equal to zero. This concept is essential for simplifying polynomial equations and finding all possible solutions.
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