Math Problem Statement

Write the expression f(x) = 2x^2 + 12x + 14 in the form f(x) = a(x + h)^2 + k, where a, h, k are real numbers. Hence, state the turning point of f(x). Calculate the values of x that are valid for the equation |(x - 2) / (x + 3)| = 4.

Solution

Let's solve the questions one by one from the image.

Part (c)

You are asked to rewrite the expression: f(x)=2x2+12x+14f(x) = 2x^2 + 12x + 14 in the form f(x)=a(x+h)2+kf(x) = a(x + h)^2 + k, where aa, hh, and kk are real numbers.

This requires us to complete the square for the expression f(x)f(x).

  1. Start with f(x)=2x2+12x+14f(x) = 2x^2 + 12x + 14.
  2. Factor out the coefficient of x2x^2, which is 2: f(x)=2(x2+6x)+14f(x) = 2(x^2 + 6x) + 14
  3. Complete the square for the expression inside the parentheses:
    • Take half of 6 (the coefficient of xx), square it, and add/subtract it inside the parentheses.
    • Half of 6 is 3, and 32=93^2 = 9.
  4. Rewrite x2+6xx^2 + 6x as: x2+6x=(x+3)29x^2 + 6x = (x + 3)^2 - 9
  5. Substitute back: f(x)=2((x+3)29)+14f(x) = 2((x + 3)^2 - 9) + 14
  6. Distribute the 2 and simplify: f(x)=2(x+3)218+14=2(x+3)24f(x) = 2(x + 3)^2 - 18 + 14 = 2(x + 3)^2 - 4 So, in the form f(x)=a(x+h)2+kf(x) = a(x + h)^2 + k, we have:
  • a=2a = 2
  • h=3h = -3
  • k=4k = -4

Thus, the rewritten form is: f(x)=2(x+3)24f(x) = 2(x + 3)^2 - 4

Turning Point of f(x)f(x)

The turning point of f(x)=2(x+3)24f(x) = 2(x + 3)^2 - 4 is given by the point (h,k)(-h, k). Here, h=3h = -3 and k=4k = -4, so the turning point is: (3,4)(-3, -4)


Part (d)

You are asked to solve for xx in the equation: x2x+3=4\left| \frac{x - 2}{x + 3} \right| = 4

This absolute value equation can be split into two cases:

Case 1: x2x+3=4\frac{x - 2}{x + 3} = 4

  1. Multiply both sides by x+3x + 3: x2=4(x+3)x - 2 = 4(x + 3)
  2. Expand and simplify: x2=4x+12x - 2 = 4x + 12
  3. Move xx terms to one side: 212=4xx-2 - 12 = 4x - x 14=3x-14 = 3x x=143x = -\frac{14}{3}

Case 2: x2x+3=4\frac{x - 2}{x + 3} = -4

  1. Multiply both sides by x+3x + 3: x2=4(x+3)x - 2 = -4(x + 3)
  2. Expand and simplify: x2=4x12x - 2 = -4x - 12
  3. Move xx terms to one side: x+4x=12+2x + 4x = -12 + 2 5x=105x = -10 x=2x = -2

Solution

The values of xx that satisfy the equation are: x=143andx=2x = -\frac{14}{3} \quad \text{and} \quad x = -2


Would you like further details on any step?


Related Questions

  1. How do you verify the turning point of a quadratic function?
  2. What are other methods for solving absolute value equations?
  3. How is completing the square useful for graphing parabolas?
  4. Can completing the square help in finding maximum or minimum values?
  5. What are some real-life applications of quadratic functions?

Tip

When solving absolute value equations, always remember to consider both positive and negative cases.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Functions
Completing the Square
Absolute Value Equations

Formulas

Standard form of a quadratic function: f(x) = ax^2 + bx + c
Vertex form of a quadratic function: f(x) = a(x + h)^2 + k
Absolute value equation |A| = B

Theorems

Properties of absolute values
Completing the square

Suitable Grade Level

Grades 10-12