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Ch. 3 - Polynomial and Rational Functions
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
Chapter 4, Problem 65

The remainder theorem indicates that when a polynomial ƒ(x) is divided by x-k, the remainder is equal to ƒ(k). Consider the polynomial function ƒ(x) = x3 - 2x2 - x+2. Use the remainder theorem to find each of the following. Then determine the coordinates of the corresponding point on the graph of ƒ(x). ƒ (-2)

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Identify the polynomial function given: \(f(x) = x^3 - 2x^2 - x + 2\).
Recall the Remainder Theorem: When a polynomial \(f(x)\) is divided by \(x - k\), the remainder is \(f(k)\).
To find \(f(-2)\), substitute \(x = -2\) into the polynomial: \(f(-2) = (-2)^3 - 2(-2)^2 - (-2) + 2\).
Simplify the expression step-by-step: calculate each term separately and then combine them.
The value \(f(-2)\) is the remainder when dividing by \(x + 2\), and the corresponding point on the graph is \((-2, f(-2))\).

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Remainder Theorem

The Remainder Theorem states that when a polynomial ƒ(x) is divided by a linear divisor of the form x - k, the remainder of this division is equal to the value of the polynomial evaluated at k, or ƒ(k). This allows for quick calculation of remainders without performing full polynomial division.
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Polynomial Evaluation

Polynomial evaluation involves substituting a specific value for the variable x in the polynomial expression and simplifying to find the output. For example, to find ƒ(-2), replace every x in the polynomial with -2 and compute the result.
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Coordinates on the Graph of a Function

The coordinates of a point on the graph of a function ƒ(x) are given by (x, ƒ(x)). After evaluating the polynomial at a specific x-value, the resulting pair represents a point on the curve, which helps visualize the function's behavior at that input.
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