Math Problem Statement

what is the domain and range of f (x) = 3- x²

Solution

For the function f(x)=3x2f(x) = 3 - x^2, let's determine the domain and range.

Domain:

The domain of a function consists of all the possible values of xx that can be input into the function. Since f(x)=3x2f(x) = 3 - x^2 is a quadratic function (a polynomial), there are no restrictions on the values of xx. Therefore, the domain is:

Domain=R(all real numbers)\text{Domain} = \mathbb{R} \quad \text{(all real numbers)}

Range:

The range of a function is the set of all possible output values. For f(x)=3x2f(x) = 3 - x^2, the function is a downward-opening parabola (since the coefficient of x2x^2 is negative). The vertex of the parabola gives the maximum value of the function.

The vertex of a quadratic function ax2+bx+cax^2 + bx + c occurs at x=b2ax = -\frac{b}{2a}. In this case, a=1a = -1, b=0b = 0, and c=3c = 3, so the vertex is at:

x=02(1)=0x = -\frac{0}{2(-1)} = 0

Substituting x=0x = 0 back into the function:

f(0)=3(0)2=3f(0) = 3 - (0)^2 = 3

Since the parabola opens downward, the maximum value is 3, and the function can take any value less than or equal to 3. Therefore, the range is:

Range=(,3]\text{Range} = (-\infty, 3]

Summary:

  • Domain: R\mathbb{R} (all real numbers)
  • Range: (,3](-\infty, 3]

Would you like more details on how to determine the domain or range, or do you have any other questions?


Here are 8 related questions to expand your understanding:

  1. How do you determine the vertex of a quadratic function?
  2. What is the significance of the sign of the coefficient of x2x^2 in determining the direction of a parabola?
  3. How do you find the x-intercepts of f(x)=3x2f(x) = 3 - x^2?
  4. What are the general steps to graph a quadratic function?
  5. How would the domain and range change if the function were f(x)=3x2f(x) = -3 - x^2?
  6. Can the function f(x)=3x2f(x) = 3 - x^2 have any maximum or minimum points other than the vertex?
  7. What is the axis of symmetry for the function f(x)=3x2f(x) = 3 - x^2?
  8. How does the range of a function relate to its

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Math Problem Analysis

Mathematical Concepts

Functions
Quadratic Functions
Domain and Range

Formulas

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Theorems

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Suitable Grade Level

Grades 9-12