Math Problem Statement

Use the vertex and intercepts to sketch the graph of the quadratic function f(x) = 2(x - 3)^2 - 1. Use the parabola to identify the function's domain and range. The axis of symmetry is x = 3.

Solution

From the image, we are analyzing a quadratic function given as:

f(x)=2(x3)21f(x) = 2(x - 3)^2 - 1

Key Features:

  1. Vertex Form: The equation f(x)=2(x3)21f(x) = 2(x - 3)^2 - 1 is already in vertex form, f(x)=a(xh)2+kf(x) = a(x - h)^2 + k, where:

    • h=3h = 3 (x-coordinate of the vertex),
    • k=1k = -1 (y-coordinate of the vertex).
    • Thus, the vertex is at (3,1)(3, -1).
  2. Axis of Symmetry: The axis of symmetry is the vertical line that passes through the vertex. Therefore: x=3x = 3

  3. Domain: A quadratic function is defined for all real numbers. Therefore, the domain is: (,)(-\infty, \infty)

  4. Range: Since a=2>0a = 2 > 0, the parabola opens upwards. The lowest point of the graph is the vertex's y-coordinate, 1-1. Thus, the range is: [1,)[-1, \infty)

Instructions for Graphing:

  • Plot the vertex at (3,1)(3, -1).

  • Use the y-intercept: Setting x=0x = 0: f(0)=2(03)21=2(9)1=181=17f(0) = 2(0 - 3)^2 - 1 = 2(9) - 1 = 18 - 1 = 17 The y-intercept is at (0,17)(0, 17).

  • Reflect points symmetrically across the axis of symmetry, x=3x = 3.


Final Answers:

  1. Axis of symmetry: x=3x = 3.
  2. Domain: (,)(-\infty, \infty).

Would you like a more detailed explanation or visualization? Here are five related questions to deepen your understanding:

  1. What is the significance of the vertex in a parabola?
  2. How does the coefficient aa in f(x)=a(xh)2+kf(x) = a(x-h)^2 + k affect the graph's shape?
  3. What steps can you take to find the intercepts of a quadratic function?
  4. How would the graph change if aa were negative?
  5. Can the vertex form of a quadratic function be converted to standard form? If so, how?

Tip: Always check the sign of aa to determine whether a parabola opens upward or downward!

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Math Problem Analysis

Mathematical Concepts

Quadratic Functions
Vertex Form
Axis of Symmetry
Domain and Range

Formulas

f(x) = a(x - h)^2 + k (Vertex Form)
Domain: (-∞, ∞) for all quadratic functions

Theorems

Axis of symmetry theorem for parabolas

Suitable Grade Level

Grades 9-12