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 35
Textbook Question
In Exercises 35–36, use the Rational Zero Theorem to list all possible rational zeros for each given function. f(x) = x^4 - 6x^3 + 14x^2 -14x + 5
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1
Identify the constant term and the leading coefficient of the polynomial. Here, the constant term is 5 and the leading coefficient is 1.
List all factors of the constant term (5). The factors are ±1, ±5.
List all factors of the leading coefficient (1). The factors are ±1.
Use the Rational Zero Theorem, which states that any rational zero of the polynomial is of the form p/q, where p is a factor of the constant term and q is a factor of the leading coefficient.
Combine the factors to list all possible rational zeros: ±1, ±5.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Rational Zero Theorem
The Rational Zero Theorem states that any rational solution (or zero) of a polynomial equation can be expressed as a fraction p/q, where p is a factor of the constant term and q is a factor of the leading coefficient. This theorem helps in identifying all possible rational zeros of a polynomial function, which can then be tested to find actual zeros.
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Factors of a Polynomial
Factors of a polynomial are the numbers or expressions that can be multiplied together to yield the polynomial. For the Rational Zero Theorem, identifying the factors of the constant term (the last term of the polynomial) and the leading coefficient (the coefficient of the highest degree term) is essential, as these factors determine the potential rational zeros.
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Testing for Zeros
Once the possible rational zeros are identified using the Rational Zero Theorem, each candidate must be tested in the polynomial function to determine if it is indeed a zero. This is typically done by substituting the candidate into the polynomial and checking if the result equals zero, which confirms that the candidate is a valid zero of the function.
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