Math Problem Statement

If the function f is a polynomial function of fourth degree and its domain is R, then the greatest number of the critical points of the function f(X) is:

Solution

The question asks about a fourth-degree polynomial function f(x)f(x), and specifically, the maximum number of critical points it can have.

Key points to solve this:

  1. Degree of the Polynomial: The polynomial is of degree 4, meaning its general form is: f(x)=ax4+bx3+cx2+dx+ef(x) = ax^4 + bx^3 + cx^2 + dx + e where a,b,c,d,ea, b, c, d, e are constants.

  2. Critical Points: Critical points occur where the first derivative f(x)f'(x) equals zero.

  3. First Derivative: The derivative of a 4th-degree polynomial is a 3rd-degree polynomial: f(x)=4ax3+3bx2+2cx+df'(x) = 4ax^3 + 3bx^2 + 2cx + d A third-degree polynomial can have at most 3 real roots (because the number of critical points corresponds to the number of real roots of f(x)f'(x)).

Therefore, the maximum number of critical points for a 4th-degree polynomial is 3.

The correct answer is: (c) 3.


Would you like more details or have any questions about the solution?

Here are 5 related questions for practice:

  1. How do you find the critical points of a function in general?
  2. What is the minimum number of critical points a 4th-degree polynomial can have?
  3. How does the degree of the first derivative affect the number of critical points?
  4. Can a polynomial of degree 3 have fewer than 3 critical points?
  5. What is the significance of a critical point in determining the behavior of a function?

Tip: The critical points help identify where the function has local maxima, minima, or saddle points (inflection points).

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Math Problem Analysis

Mathematical Concepts

Polynomial Functions
Critical Points
Derivatives

Formulas

General form of a 4th-degree polynomial: f(x) = ax^4 + bx^3 + cx^2 + dx + e
First derivative of f(x): f'(x) = 4ax^3 + 3bx^2 + 2cx + d

Theorems

The Fundamental Theorem of Algebra

Suitable Grade Level

Grade 11-12 or College