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Ch. 3 - Polynomial and Rational Functions
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 4, Problem 49

In Exercises 49–50, find all the zeros of each polynomial function and write the polynomial as a product of linear factors. f(x)=2x4+3x3+3x2f(x) = 2x^4 + 3x^3 + 3x - 2

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First, write down the polynomial function: \(f(x) = 2x^4 + 3x^3 + 3x - 2\).
Look for possible rational zeros using the Rational Root Theorem. The possible rational zeros are of the form \(\pm \frac{p}{q}\), where \(p\) divides the constant term \(-2\) and \(q\) divides the leading coefficient \(2\). So possible zeros are \(\pm 1\), \(\pm 2\), \(\pm \frac{1}{2}\).
Test each possible rational zero by substituting into \(f(x)\) or by using synthetic division to check if it yields a remainder of zero. When you find a zero, say \(r\), factor out \((x - r)\) from the polynomial.
After factoring out one linear factor, divide the original polynomial by this factor to get a cubic polynomial. Repeat the process of finding zeros and factoring until the polynomial is expressed as a product of linear factors.
Once all zeros are found and the polynomial is factored completely, write the polynomial as \(f(x) = a(x - r_1)(x - r_2)(x - r_3)(x - r_4)\), where \(a\) is the leading coefficient and \(r_1, r_2, r_3, r_4\) are the zeros.

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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 these roots helps in understanding the behavior of the function and is essential for factoring the polynomial into linear factors.
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Factoring Polynomials

Factoring involves expressing a polynomial as a product of simpler polynomials, ideally linear factors. This process often uses the zeros of the polynomial, allowing it to be written as (x - r) for each root r.
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Rational Root Theorem and Synthetic Division

The Rational Root Theorem helps identify possible rational zeros by considering factors of the constant and leading coefficients. Synthetic division is a streamlined method to test these candidates and simplify the polynomial for further factoring.
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