Math Problem Statement

Find the zeros for the polynomial function f(x) = 6(x - 9)(x + 4)^2 and give the multiplicity for each zero. State whether the graph crosses the x-axis or touches the x-axis and turns around at each zero.

Solution

The problem asks for the zeros of the polynomial function:

f(x)=6(x9)(x+4)2f(x) = 6(x - 9)(x + 4)^2

Steps to find the zeros and their multiplicities:

  1. Set f(x)=0f(x) = 0 to find the zeros: 6(x9)(x+4)2=06(x - 9)(x + 4)^2 = 0 This equation is satisfied if either factor equals zero.

  2. Solve for each factor:

    • For x9=0x - 9 = 0, the solution is x=9x = 9. This zero has multiplicity 1 (because the exponent on this factor is 1).
    • For (x+4)2=0(x + 4)^2 = 0, the solution is x=4x = -4. This zero has multiplicity 2 (because the exponent is 2).

Zeros and their multiplicities:

  • Zero at x=9x = 9, with multiplicity 1.
  • Zero at x=4x = -4, with multiplicity 2.

Behavior at the x-axis:

  • At x=9x = 9, since the multiplicity is 1 (odd), the graph crosses the x-axis.
  • At x=4x = -4, since the multiplicity is 2 (even), the graph touches the x-axis and turns around.

Final answer:

The zeros are x=9x = 9 and x=4x = -4.

Would you like more details or explanations on any step? Here are some related questions:

  1. What is the general relationship between multiplicity and the graph's behavior at zeros?
  2. How do higher-order multiplicities (greater than 2) affect the graph at the x-axis?
  3. Can you always factor polynomials like this easily?
  4. What happens if a polynomial has complex roots?
  5. How does the degree of the polynomial affect the number of zeros?

Tip: The graph crosses the x-axis at zeros with odd multiplicity and touches (but does not cross) at zeros with even multiplicity!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Polynomial Functions
Zeros of Functions
Multiplicity

Formulas

f(x) = 6(x - 9)(x + 4)^2

Theorems

Zero-Multiplicity Theorem

Suitable Grade Level

Grades 9-12