Chapter 3: Problem 60
Find a polynomial of the specified degree that has the given zeros. Degree \(5 ; \quad\) zeros \(-2,-1,0,1,2\)
Short Answer
Expert verified
The polynomial is \(P(x) = x^5 - 9x^3 + 4x\).
Step by step solution
01
Write Down the General Form of the Polynomial
The polynomial is expressed as a product of its factors, each corresponding to a zero. If a polynomial has zeros at \(-2, -1, 0, 1,\) and \(2\), its general form is \[ P(x) = a(x + 2)(x + 1)x(x - 1)(x - 2) \] where \(a\) is a non-zero constant.
02
Expand the Polynomial
First, multiply the factors in two pairs and then include the standalone term:\[ (x + 2)(x + 1) = x^2 + 3x + 2 \]\[ (x - 1)(x - 2) = x^2 - 3x + 2 \]Multiplying these results gives:\[ (x^2 + 3x + 2)(x^2 - 3x + 2) = x^4 - 9x^2 + 4 \]
03
Multiply by the Remaining Factor
Now, include the remaining factor \(x\) to the expression from Step 2:\[ x(x^4 - 9x^2 + 4) = x^5 - 9x^3 + 4x \]
04
Consider the Leading Coefficient
The constant \(a\) can be any non-zero number, typically chosen to be 1 for simplicity unless stated otherwise. Thus, the polynomial with the given zeros is:\[ P(x) = x^5 - 9x^3 + 4x \]
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Degree of a Polynomial
Polynomials are algebraic expressions that consist of variables and coefficients, combined using addition, subtraction, and multiplication operations. One of the key characteristics of a polynomial is its degree.
- The degree of a polynomial is the highest power of the variable within the expression.
- For instance, in the polynomial expression \( x^5 - 9x^3 + 4x \), the degree is 5, because the term \( x^5 \) has the highest exponent.
- The degree gives an idea of how the polynomial behaves as the variable gets larger or smaller.
Zeros of a Polynomial
The zeros (or roots) of a polynomial are the values of the variable that make the polynomial equal to zero. Finding these zeros is fundamental in understanding the solutions and behavior of polynomial equations.
- Zeros are typically obtained by solving the equation where the polynomial is equal to zero, \( P(x) = 0 \).
- For example, in our exercise, the polynomial \( P(x) \) has the zeros \(-2, -1, 0, 1,\) and \(2\).
- These zeros indicate where the polynomial will intersect the x-axis on a graph.
Expanding Polynomials
Once we have a polynomial in its factored form, expanding it into a standard polynomial form involves multiplying the factors together.
- Expanding is the process where each factor is multiplied with every other factor to simplify and combine them into a single polynomial expression.
- This is done step-by-step, often starting with two simpler factors and then progressively including others.
- In our solution, we first expanded \((x+2)(x+1)\) and then \((x-1)(x-2)\), and combined these into larger expressions.
- Afterwards, the result is multiplied with the remaining linear factor, \(x\), to get a single polynomial expression.
Factored Form of a Polynomial
A polynomial in its factored form is expressed as a product of its linear factors, each corresponding to a zero of the polynomial. This form is quite useful for a number of reasons.
- Factored form directly shows the zeros, making it easy to understand the roots of the polynomial.
- For example, given the zeros \(-2, -1, 0, 1,\) and \(2\), the factored form is \((x+2)(x+1)x(x-1)(x-2)\).
- Handling polynomials in factored form is advantageous during division, simplification, and finding least common multiples.