Math Problem Statement

Transform the given quadratic functions in general form into vertex form. Find the constants a, h, and k.

Solution

The task involves converting quadratic functions from their general form y=ax2+bx+cy = ax^2 + bx + c into vertex form y=a(xh)2+ky = a(x - h)^2 + k, where hh and kk represent the coordinates of the vertex, and aa is the same as the leading coefficient in both forms.

Here are the steps to convert each equation to vertex form by completing the square:

1. y=x26x6y = x^2 - 6x - 6

  • Start by focusing on x26xx^2 - 6x.
  • Take half of 6-6, square it, and add it inside the equation: (62)2=9\left( \frac{-6}{2} \right)^2 = 9.
  • Add and subtract 9: y=(x26x+9)96y = (x^2 - 6x + 9) - 9 - 6.
  • This simplifies to: y=(x3)215y = (x - 3)^2 - 15.

Thus, the vertex form is:
y=(x3)215y = (x - 3)^2 - 15 So, a=1a = 1, h=3h = 3, and k=15k = -15.

2. y=x2+4x10y = x^2 + 4x - 10

  • Focus on x2+4xx^2 + 4x.
  • Take half of 4, square it, and add it: (42)2=4\left( \frac{4}{2} \right)^2 = 4.
  • Add and subtract 4: y=(x2+4x+4)410y = (x^2 + 4x + 4) - 4 - 10.
  • Simplifies to: y=(x+2)214y = (x + 2)^2 - 14.

Thus, the vertex form is:
y=(x+2)214y = (x + 2)^2 - 14
So, a=1a = 1, h=2h = -2, and k=14k = -14.

3. y=3x218x+2y = 3x^2 - 18x + 2

  • Factor out 3 from the first two terms: y=3(x26x)+2y = 3(x^2 - 6x) + 2.
  • Complete the square inside the parentheses: (62)2=9\left( \frac{-6}{2} \right)^2 = 9.
  • Add and subtract 9×39 \times 3 inside: y=3(x26x+9)27+2y = 3(x^2 - 6x + 9) - 27 + 2.
  • Simplifies to: y=3(x3)225y = 3(x - 3)^2 - 25.

Thus, the vertex form is:
y=3(x3)225y = 3(x - 3)^2 - 25
So, a=3a = 3, h=3h = 3, and k=25k = -25.

4. y=x216x+14y = x^2 - 16x + 14

  • Focus on x216xx^2 - 16x.
  • Half of 16-16 is 8-8, and (162)2=64\left( \frac{-16}{2} \right)^2 = 64.
  • Add and subtract 64: y=(x216x+64)64+14y = (x^2 - 16x + 64) - 64 + 14.
  • Simplifies to: y=(x8)250y = (x - 8)^2 - 50.

Thus, the vertex form is:
y=(x8)250y = (x - 8)^2 - 50
So, a=1a = 1, h=8h = 8, and k=50k = -50.

5. y=2x2+8x13y = 2x^2 + 8x - 13

  • Factor out 2 from the first two terms: y=2(x2+4x)13y = 2(x^2 + 4x) - 13.
  • Complete the square inside: (42)2=4\left( \frac{4}{2} \right)^2 = 4.
  • Add and subtract 4×24 \times 2: y=2(x2+4x+4)813y = 2(x^2 + 4x + 4) - 8 - 13.
  • Simplifies to: y=2(x+2)221y = 2(x + 2)^2 - 21.

Thus, the vertex form is:
y=2(x+2)221y = 2(x + 2)^2 - 21
So, a=2a = 2, h=2h = -2, and k=21k = -21.


Would you like more details on any step? Here are some related questions to explore:

  1. How is completing the square useful for solving quadratic equations?
  2. Can vertex form help in graphing quadratic functions more easily?
  3. What is the geometric significance of the constants hh and kk?
  4. How does factoring differ from completing the square in quadratic transformations?
  5. What are some real-life applications of quadratic functions?

Tip: Always double-check your constants when completing the square to avoid mistakes.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
Completing the Square

Formulas

General form of quadratic equation: y = ax^2 + bx + c
Vertex form of quadratic equation: y = a(x - h)^2 + k
Process of completing the square

Theorems

Vertex Formula

Suitable Grade Level

High School