Math Problem Statement

Tentukan persamaan bayangan dari fungsi f(x) = (x - 1) / (4x + 2), x ≠ -1/2, jika direfleksikan terhadap a. Garis y = x b. Garis y = -x

Solution

The problem in the image asks to determine the reflection of the function f(x)=x14x+2,x12f(x) = \frac{x - 1}{4x + 2}, x \neq -\frac{1}{2}, across two different lines:

  1. Reflection over the line y=xy = x.
  2. Reflection over the line y=xy = -x.

1. Reflection over the line y=xy = x:

To reflect the function f(x)f(x) over the line y=xy = x, we swap xx and yy, and solve for yy.

Given: y=x14x+2y = \frac{x - 1}{4x + 2} We swap xx and yy: x=y14y+2x = \frac{y - 1}{4y + 2} Now solve for yy: x(4y+2)=y1x(4y + 2) = y - 1 4xy+2x=y14xy + 2x = y - 1 4xyy=2x14xy - y = -2x - 1 y(4x1)=2x1y(4x - 1) = -2x - 1 y=2x14x1y = \frac{-2x - 1}{4x - 1} Thus, the equation of the reflection of f(x)f(x) over the line y=xy = x is: f1(x)=2x14x1f^{-1}(x) = \frac{-2x - 1}{4x - 1}

2. Reflection over the line y=xy = -x:

To reflect f(x)f(x) over the line y=xy = -x, we follow a similar process, but now swap xx with y-y.

Starting with: y=x14x+2y = \frac{x - 1}{4x + 2} Swap xx and y-y: x=y14(y)+2=y14y+2x = \frac{-y - 1}{4(-y) + 2} = \frac{-y - 1}{-4y + 2} Solve for yy: x(4y+2)=y1x(-4y + 2) = -y - 1 4xy+2x=y1-4xy + 2x = -y - 1 4xy+y=2x1-4xy + y = -2x - 1 y(4x+1)=2x1y(-4x + 1) = -2x - 1 y=2x14x+1=2x+14x1y = \frac{-2x - 1}{-4x + 1} = \frac{2x + 1}{4x - 1} Thus, the reflection of f(x)f(x) over the line y=xy = -x is: frefl(x)=2x+14x1f_{refl}(x) = \frac{2x + 1}{4x - 1}


Would you like further clarification on any step? Also, here are some related questions you could explore:

  1. How do you find the inverse of a general function?
  2. What happens to the domain and range when a function is reflected over y=xy = x?
  3. How do reflections affect the asymptotes of rational functions?
  4. What are the graphical implications of reflecting a function over y=xy = -x?
  5. How can we verify the correctness of a reflection algebraically?

Tip: Reflections over lines like y=xy = x or y=xy = -x often involve swapping variables and solving, making inverse function techniques particularly useful.

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Math Problem Analysis

Mathematical Concepts

Function reflection
Inverse functions
Rational equations

Formulas

Reflection across y = x: Swap x and y, solve for y
Reflection across y = -x: Swap x and -y, solve for y

Theorems

Inverse function theorem
Properties of reflections

Suitable Grade Level

Grades 10-12