Math Problem Statement

The figure shows the graph of y = 3x^2 - 6x + (k - 2) with the axis of symmetry x = 1. Determine the value of k.

Solution

The problem states that the figure shows the graph of the quadratic equation:

y=3x26x+(k2)y = 3x^2 - 6x + (k - 2)

with the axis of symmetry at x=1x = 1. Let's analyze the situation:


Step 1: General Formula for Axis of Symmetry

For a quadratic equation of the form: y=ax2+bx+c,y = ax^2 + bx + c, the axis of symmetry is given by: x=b2a.x = -\frac{b}{2a}.

In this case: a=3,b=6,c=k2.a = 3, \quad b = -6, \quad c = k - 2.


Step 2: Plugging in the Axis of Symmetry

The problem specifies the axis of symmetry is at x=1x = 1. Thus: 1=62(3).1 = -\frac{-6}{2(3)}.

This confirms that the quadratic is correctly set up, as the axis of symmetry depends only on aa and bb, and is independent of cc.


Step 3: Determine the Vertex

The axis of symmetry passes through the vertex of the parabola. Substituting x=1x = 1 into the quadratic equation: y=3(1)26(1)+(k2).y = 3(1)^2 - 6(1) + (k - 2). Simplifying: y=36+(k2),y = 3 - 6 + (k - 2), y=k5.y = k - 5.

Thus, the vertex is at: (1,k5).(1, k - 5).


Step 4: Analyze the Graph and Solve for kk

From the graph, it appears that the vertex lies on the horizontal axis (y=0y = 0). Hence: k5=0,k - 5 = 0, k=5.k = 5.


Final Answer:

The value of kk is: 5.\boxed{5}.


Would you like further clarification or details on this? Here are five related questions to deepen understanding:

  1. How do we determine the axis of symmetry for any quadratic equation?
  2. Why does the vertex always lie on the axis of symmetry?
  3. What is the significance of the k2k - 2 term in this quadratic equation?
  4. How do the graph’s roots relate to its vertex and axis of symmetry?
  5. How does changing kk affect the graph of the quadratic function?

Tip: Always double-check the graph's key points, like the vertex and axis of symmetry, to confirm your solutions!

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Math Problem Analysis

Mathematical Concepts

Quadratic Functions
Axis of Symmetry
Vertex Form

Formulas

Axis of symmetry formula: x = -b / 2a
Quadratic equation: y = ax^2 + bx + c

Theorems

Properties of Quadratic Functions

Suitable Grade Level

Grades 9-10