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
Dividing Polynomials
Problem 19
Textbook Question
In Exercises 17–32, divide using synthetic division. (3x^2+7x−20)÷(x+5)
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1
Identify the divisor and the dividend. The divisor is \(x + 5\) and the dividend is \(3x^2 + 7x - 20\).
Set the divisor equal to zero to find the root: \(x + 5 = 0\), so \(x = -5\). This is the number we will use in synthetic division.
Write down the coefficients of the dividend: \(3, 7, -20\).
Perform synthetic division: Bring down the first coefficient (3) as it is. Multiply it by the root (-5) and add to the next coefficient (7). Repeat this process for the remaining coefficients.
The result will give you the coefficients of the quotient polynomial and a remainder, if any.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Synthetic Division
Synthetic division is a simplified method for dividing polynomials, particularly useful when dividing by linear factors. It involves using the coefficients of the polynomial and a specific value derived from the divisor to perform the division in a streamlined manner, avoiding the more complex long division process.
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Polynomial Functions
A polynomial function is a mathematical expression involving a sum of powers in one or more variables multiplied by coefficients. In this case, the polynomial 3x^2 + 7x - 20 is a quadratic function, which is essential to understand as it represents the dividend in the division process.
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Remainder Theorem
The Remainder Theorem states that when a polynomial f(x) is divided by a linear divisor of the form (x - c), the remainder of this division is equal to f(c). This theorem is useful in synthetic division as it helps to quickly determine the remainder without performing the entire division process.
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