Math Problem Statement

The graph shows a polynomial function f. Polynomial function g is defined by g(x) = x^2(9 - x). Compare the maximum values and the end behavior of the functions f and g when x > 0.

Solution

Analysis of the Problem:

We are tasked with comparing the maximum values of f(x)f(x) and g(x)g(x), as well as comparing their end behavior when x>0x > 0.

From the given information:

  • g(x)=x2(9x)g(x) = x^2 (9 - x)
  • The graph shows f(x)f(x), a polynomial function, with its maximum value and shape provided.

Step 1: Compare Maximum Values

f(x)f(x)

  • From the graph of f(x)f(x), the maximum value occurs at y=100y = 100 when x>0x > 0.

g(x)g(x)

  1. The function g(x)=x2(9x)g(x) = x^2 (9 - x) is a cubic polynomial.
  2. To find the maximum value of g(x)g(x) for x>0x > 0, take the derivative: g(x)=2x(9x)x2=18x3x2g'(x) = 2x(9 - x) - x^2 = 18x - 3x^2
  3. Set g(x)=0g'(x) = 0: 18x3x2=0    x(183x)=018x - 3x^2 = 0 \implies x(18 - 3x) = 0 Solving gives x=0x = 0 or x=6x = 6.
  4. Evaluate g(x)g(x) at x=6x = 6: g(6)=62(96)=363=108g(6) = 6^2 (9 - 6) = 36 \cdot 3 = 108

Thus, the maximum value of g(x)g(x) is 108, which is greater than the maximum value of f(x)=100f(x) = 100.


Step 2: Compare End Behavior

End Behavior of f(x)f(x)

  • From the graph, as xx \to \infty, f(x)f(x) \to -\infty.

End Behavior of g(x)g(x)

  • Analyze the degree and leading term of g(x)=x2(9x)g(x) = x^2 (9 - x): g(x)=x3+9x2g(x) = -x^3 + 9x^2 The leading term is x3-x^3, which dominates as xx \to \infty. Thus: As x,g(x).\text{As } x \to \infty, g(x) \to -\infty.

Conclusion on End Behavior:

  • For both f(x)f(x) and g(x)g(x), as xx \to \infty, yy \to -\infty.

Final Answers:

  1. Maximum values:

    • The maximum value of f(x)f(x) is 100, which is less than the maximum value of g(x)=108g(x) = 108.
  2. End behavior:

    • The correct choice is C: "For both functions, when x,yx \to \infty, y \to -\infty."

Do you want details or have further questions?

Here are 5 related questions for deeper exploration:

  1. How do we confirm that g(x)=x2(9x)g(x) = x^2 (9 - x) has no other maximum points for x>0x > 0?
  2. Can we determine the specific point at which f(x)f(x) achieves its maximum value?
  3. How does the degree of a polynomial affect its end behavior?
  4. What are the intercepts of g(x)g(x), and how do they compare to those of f(x)f(x)?
  5. How do the critical points of g(x)g(x) influence its shape and maximum value?

Tip: Always double-check derivatives and critical points when analyzing maximum or minimum values for functions!

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Math Problem Analysis

Mathematical Concepts

Polynomials
End Behavior
Derivatives
Critical Points

Formulas

Derivative of a function
Critical points calculation

Theorems

Fundamental Theorem of Calculus
Polynomial End Behavior

Suitable Grade Level

Grades 11-12