(x+6)^2(x+1)(x-8)^2

5 min read Jun 17, 2024
(x+6)^2(x+1)(x-8)^2

Analyzing the Polynomial: (x+6)^2(x+1)(x-8)^2

This polynomial is a product of four factors:

  • (x+6)^2: This factor contributes a double root at x = -6.
  • (x+1): This factor contributes a single root at x = -1.
  • (x-8)^2: This factor contributes a double root at x = 8.

Let's explore the characteristics of this polynomial:

Roots and Multiplicity

The roots of a polynomial are the values of x that make the polynomial equal to zero. The multiplicity of a root tells us how many times the corresponding factor appears in the polynomial.

Here's a table summarizing the roots and their multiplicities:

Root Multiplicity
-6 2
-1 1
8 2

Key Point: The multiplicity of a root affects the behavior of the graph at that point.

  • Odd Multiplicity: The graph crosses the x-axis at the root.
  • Even Multiplicity: The graph touches the x-axis at the root but does not cross it.

End Behavior

The end behavior of a polynomial is determined by its leading term. To find the leading term, we multiply the leading terms of each factor:

(x+6)^2(x+1)(x-8)^2 = (x^2)(x)(x^2) = x^5

Since the leading term has an odd degree and a positive coefficient, the end behavior is:

  • As x approaches negative infinity, y approaches negative infinity.
  • As x approaches positive infinity, y approaches positive infinity.

Graphing the Polynomial

Based on the information above, we can sketch a rough graph of the polynomial.

  1. Mark the roots: Plot the points (-6, 0), (-1, 0), and (8, 0) on the x-axis.
  2. Consider multiplicity: The graph will touch but not cross the x-axis at x = -6 and x = 8 (due to even multiplicity). The graph will cross the x-axis at x = -1 (due to odd multiplicity).
  3. End behavior: The graph will start in the bottom left quadrant and end in the top right quadrant.

Important Note: This is a rough sketch. The exact shape of the graph would require a more detailed analysis.

Further Exploration

To fully understand the behavior of this polynomial, we could also analyze:

  • Turning points: The number of turning points in a polynomial is at most one less than its degree.
  • Intervals of increasing and decreasing: We can identify the intervals where the function is increasing or decreasing.
  • Local maxima and minima: These are the points where the function reaches a peak or valley.

This polynomial provides a good example of how the factors and their multiplicities contribute to the behavior of a function. Understanding these concepts is essential for analyzing and graphing polynomials.

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