Use the Transformations of Functions portfolio worksheet to record your answers to the following questions. When you are finished, save your worksheet with your answers, and submit it for a portfolio grade. Where indicated, draw figures on a blank sheet of paper or on a sheet of graph paper. Be sure to label each sheet so that your teacher knows which answer goes with which question. You can scan these figures and submit them as individual documents with your portfolio worksheet, or you can take pictures of them and insert the pictures on the portfolio worksheet. Question 1 On a sheet of graph paper, sketch a graph of each of the following parent functions. Clearly label each parent function with its equation and its name (e.g. “Exponential Function”). f(x)=x f(x)=x2 f(x)=2x f(x)=x−−√ f(x)=x−−√3 Explain the meaning of the terms “parent function” and “function family.” Question 2 Consider the relationship between y=f(x) and y=−f(x) . What is this type of function transformation called? What does it look like on a graph? Choose one of the parent functions from Question 1. On a sheet of graph paper, sketch both y=f(x) and y=−f(x) or your chosen parent function. Be sure to clearly label each sketch. Question 3 Consider the relationship between y=f(x) and y=f(−x) . What is this type of function transformation called? What does it look like on a graph? Choose one of the parent functions from Question 1. On a sheet of graph paper, sketch both y=f(x) and y=f(−x) for your chosen parent function. Be sure to clearly label each sketch. Question 4 What makes a function an even function? On a sheet of graph paper, sketch an example of an even function. What make a function an odd function? On a sheet of graph paper, sketch an example of an odd function. Are all functions either even functions or odd functions? Explain. You may include a sketch of a graph in your response if you wish. Question 5 Consider the relationship between y=f(x) and y=f(x)±k . What is this type of function transformation called? What does it look like on a graph? Choose one of the parent functions from Question 1 and a value for k . On a sheet of graph paper, sketch both y=f(x) and y=f(x)±k for your chosen parent function and chosen value of k. Be sure to clearly label each sketch. Question 6 Consider the relationship between y=f(x) and y=f(x±k) . What is this type of function transformation called? What does it look like on a graph? Choose one of the parent functions from Question 1 and a value for k . On a sheet of graph paper, sketch both y=f(x) and y=f(x±k) for your chosen parent function and chosen value of k . Be sure to clearly label each sketch. Question 7 Consider the relationship between y=f(x) and y=kf(x) . What is this type of function transformation called? What does it look like on a graph? Choose one of the parent functions from Question 1 and a value for k . On a sheet of graph paper, sketch both y=f(x) and y=kf(x) for your chosen parent function and chosen value of k . Be sure to clearly label each sketch. Question 8 Consider the relationship between y=f(x) and y=f(kx) . What is this type of function transformation called? What does it look like on a graph? Choose one of the parent functions from Question 1 and a value for k . On a sheet of graph paper, sketch both y=f(x) and y=f(kx) for your chosen parent function and chosen value of k . Be sure to clearly label each sketch. Question 9 Describe the transformations between y=x−−√ and y=−x+1−−−−√+5 . Describe the transformations between y=x−−√ and y=−(x+1−−−−√+5) . Compare and contrast the transformations of the functions in parts A and B. What’s the same? What’s different?

1 answer

Certainly! Below is a guide to answering each question for your portfolio worksheet. You'll need to create sketches on graph paper for several of these questions. I've provided explanations and guidelines for each question.

Question 1: Parent Functions and Families

Parent Functions:

  • Linear Function: \( f(x) = x \)
  • Quadratic Function: \( f(x) = x^2 \)
  • Exponential Function: \( f(x) = 2^x \)
  • Square Root Function: \( f(x) = \sqrt{x} \)
  • Cube Root Function: \( f(x) = \sqrt[3]{x} \)

Definitions:

  • Parent Function: The simplest function of a particular type that retains the essential characteristics of that family of functions (e.g., \( f(x) = x^2 \) is the parent function of quadratic functions).
  • Function Family: A group of functions that share common characteristics and can be derived from a parent function by transformations (e.g., linear functions include \( f(x) = x + b \), where \( b \) is a constant).

Question 2: Transformation \( y = -f(x) \)

  • Transformation Name: Reflection across the x-axis.
  • Graph: Sketch both \( y = f(x) \) and \( y = -f(x) \) for one chosen parent function, e.g., \( y = x^2 \): The original graph is a parabola opening upwards, and the reflection opens downwards.

Question 3: Transformation \( y = f(-x) \)

  • Transformation Name: Reflection across the y-axis.
  • Graph: Sketch both \( y = f(x) \) and \( y = f(-x) \) for your chosen parent function, e.g., \( y = x^2 \): Both graphs will be symmetrical about the y-axis since \( x^2 \) is an even function.

Question 4: Even and Odd Functions

  • Even Function: A function where \( f(x) = f(-x) \). Example: \( f(x) = x^2 \). Graph will be symmetrical about the y-axis.
  • Odd Function: A function where \( f(-x) = -f(x) \). Example: \( f(x) = x^3 \). Graph will be symmetrical about the origin.

Answer: Not all functions are either even or odd; some functions may not exhibit these symmetries, like \( f(x) = x + 1 \).

Question 5: Transformation \( y = f(x) \pm k \)

  • Transformation Name: Vertical shift.
  • Graph: Choose a parent function and a \( k \) value (e.g., for \( f(x) = x^2 \) and \( k = 3 \), sketch \( y = f(x) \) and \( y = f(x) + 3 \), which shifts the graph up by 3 units).

Question 6: Transformation \( y = f(x \pm k) \)

  • Transformation Name: Horizontal shift.
  • Graph: Choose a parent function and a \( k \) value (e.g., for \( f(x) = x^2 \), sketch \( y = f(x) \) and \( y = f(x - 2) \), which shifts the graph right by 2 units).

Question 7: Transformation \( y = kf(x) \)

  • Transformation Name: Vertical stretch or compression.
  • Graph: Choose a parent function and a \( k \) value (e.g., for \( f(x) = x^2 \) and \( k = 2 \), sketch both \( y = x^2 \) and \( y = 2x^2 \), which will stretch the graph vertically).

Question 8: Transformation \( y = f(kx) \)

  • Transformation Name: Horizontal stretch or compression.
  • Graph: Choose a parent function and a \( k \) value (e.g., for \( f(x) = x^2 \) and \( k = 0.5 \), sketch both \( y = x^2 \) and \( y = f(0.5x) \), which compresses the graph horizontally).

Question 9: Comparing Transformations

  • Transformations of \( y = \sqrt{x} \) to \( y = -\sqrt{x} + 1 + 5 \):

    • Reflection across the x-axis, shift up by 6 units.
  • Transformations of \( y = \sqrt{x} \) to \( y = -(\sqrt{x} + 1) + 5 \):

    • Shift left by 1 unit, reflection across the x-axis and then shift up by 5 units.
  • Comparison:

    • Same: Both transformations involve a reflection over the x-axis.
    • Different: The first is a simple up shift of the reflected function, while the second includes both a left shift and a different vertical adjustment.

Final Steps:

  • Draw all required sketches on graph paper and label them clearly.
  • Save your worksheet and sketches and submit as instructed.

Feel free to ask for further clarification or help with any specific sketches or concepts!