Math Problem Statement

Solution

The image contains two questions regarding the domain and range of given functions. Let's address each question in detail:

  1. What is the domain and range of f(x)=3xx2f(x) = 3x - x^2?

To determine the domain and range of the function f(x)=3xx2f(x) = 3x - x^2, let's analyze it step-by-step.

Domain of f(x)=3xx2f(x) = 3x - x^2

The domain of a function includes all the possible values of xx for which the function is defined. Since f(x)=3xx2f(x) = 3x - x^2 is a polynomial, it is defined for all real numbers xx. Thus, the domain is: Domain=(,)\text{Domain} = (-\infty, \infty)

Range of f(x)=3xx2f(x) = 3x - x^2

To find the range, we need to identify the possible values of f(x)f(x).

  1. Find the vertex of the parabola: The function f(x)=3xx2f(x) = 3x - x^2 is a downward-opening parabola (since the coefficient of x2x^2 is negative). The vertex form of a quadratic function ax2+bx+cax^2 + bx + c has its vertex at x=b2ax = -\frac{b}{2a}.

    For f(x)=x2+3xf(x) = -x^2 + 3x: a=1,b=3a = -1, \quad b = 3 x=32(1)=32x = -\frac{3}{2(-1)} = \frac{3}{2}

  2. Find the maximum value of f(x)f(x): Substitute x=32x = \frac{3}{2} back into the function to find f(32)f \left( \frac{3}{2} \right): f(32)=3(32)(32)2=9294=9294=18494=94=2.25f \left( \frac{3}{2} \right) = 3 \left( \frac{3}{2} \right) - \left( \frac{3}{2} \right)^2 = \frac{9}{2} - \frac{9}{4} = \frac{9}{2} - \frac{9}{4} = \frac{18}{4} - \frac{9}{4} = \frac{9}{4} = 2.25

The maximum value of f(x)f(x) is 2.25, and since the parabola opens downwards, the range is: Range=(,2.25]\text{Range} = (-\infty, 2.25]

  1. Find the domain and range of f(x)=4f(x) = 4 using its graph.

Domain of f(x)=4f(x) = 4

The function f(x)=4f(x) = 4 is a constant function, meaning it is defined for all real numbers xx. Thus, the domain is: Domain=(,)\text{Domain} = (-\infty, \infty)

Range of f(x)=4f(x) = 4

Since f(x)=4f(x) = 4 is a constant function, it only takes on the value 4, regardless of the input xx. Thus, the range is: Range={4}\text{Range} = \{ 4 \}

Do you have any questions or need more details on any of these solutions?

Here are some related questions to further your understanding:

  1. How do you determine the domain of a rational function?
  2. What is the significance of the vertex in a quadratic function's graph?
  3. How do you find the vertex of a quadratic function given in standard form?
  4. Can the range of a quadratic function ever be all real numbers?
  5. How would the function f(x)=3xx2+5f(x) = 3x - x^2 + 5 differ in terms of domain and range?
  6. What is the general process for finding the range of a function?
  7. How do transformations (shifts, stretches) affect the domain and range of a function?
  8. Can the range of a linear function be a single value?

Tip: For polynomial functions, the domain is always all real numbers unless specified otherwise by a context or additional constraints.

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Math Problem Analysis

Mathematical Concepts

Functions
Quadratic Functions
Constant Functions
Domain and Range

Formulas

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Theorems

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Suitable Grade Level

Grades 9-12