Learn on PengiBig Ideas Math, Algebra 2Chapter 4: Polynomial Functions

Lesson 7: Transformations of Polynomial Functions

In this Grade 8 lesson from Big Ideas Math Algebra 2, students learn how to describe and write transformations of polynomial functions, including horizontal and vertical translations, reflections over the x- and y-axes, and horizontal and vertical stretches and shrinks. Using cubic and quartic parent functions such as f(x) = x³ and f(x) = x⁴, students practice identifying transformation rules expressed in function notation like f(x − h), f(x) + k, a·f(x), and f(ax). The lesson connects polynomial transformations to previously learned techniques applied to linear, absolute value, and quadratic functions.

Section 1

Graph Quadratic Functions of the form f(x) = x^2 + k

Property

The graph of f(x)=x2+kf(x) = x^2 + k shifts the graph of f(x)=x2f(x) = x^2 vertically kk units.

  • If k>0k > 0, shift the parabola vertically up kk units.
  • If k<0k < 0, shift the parabola vertically down k|k| units.

Examples

  • To graph f(x)=x2+4f(x) = x^2 + 4, you start with the graph of f(x)=x2f(x) = x^2 and shift it vertically up 4 units because k=4k = 4.
  • To graph f(x)=x25f(x) = x^2 - 5, you start with the graph of f(x)=x2f(x) = x^2 and shift it vertically down 5 units because k=5k = -5.

Section 2

Graph Quadratic Functions of the form f(x) = (x - h)^2

Property

The graph of f(x)=(xh)2f(x) = (x - h)^2 shifts the graph of f(x)=x2f(x) = x^2 horizontally hh units.

  • If h>0h > 0, shift the parabola horizontally right hh units.
  • If h<0h < 0, shift the parabola horizontally left h|h| units.

Examples

  • To graph f(x)=(x3)2f(x) = (x - 3)^2, you shift the graph of f(x)=x2f(x) = x^2 to the right 3 units. The vertex moves from (0,0)(0, 0) to (3,0)(3, 0).
  • To graph f(x)=(x+4)2f(x) = (x + 4)^2, you rewrite it as f(x)=(x(4))2f(x) = (x - (-4))^2. This means you shift the graph of f(x)=x2f(x) = x^2 to the left 4 units.

Book overview

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Chapter 4: Polynomial Functions

  1. Lesson 1

    Lesson 1: Graphing Polynomial Functions

  2. Lesson 2

    Lesson 2: Adding, Subtracting, and Multiplying Polynomials

  3. Lesson 3

    Lesson 3: Dividing Polynomials

  4. Lesson 4

    Lesson 4: Factoring Polynomials

  5. Lesson 5

    Lesson 5: Solving Polynomial Equations

  6. Lesson 6

    Lesson 6: The Fundamental Theorem of Algebra

  7. Lesson 7Current

    Lesson 7: Transformations of Polynomial Functions

  8. Lesson 8

    Lesson 8: Analyzing Graphs of Polynomial Functions

  9. Lesson 9

    Lesson 9: Modeling with Polynomial Functions

Lesson overview

Expand to review the lesson summary and core properties.

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Section 1

Graph Quadratic Functions of the form f(x) = x^2 + k

Property

The graph of f(x)=x2+kf(x) = x^2 + k shifts the graph of f(x)=x2f(x) = x^2 vertically kk units.

  • If k>0k > 0, shift the parabola vertically up kk units.
  • If k<0k < 0, shift the parabola vertically down k|k| units.

Examples

  • To graph f(x)=x2+4f(x) = x^2 + 4, you start with the graph of f(x)=x2f(x) = x^2 and shift it vertically up 4 units because k=4k = 4.
  • To graph f(x)=x25f(x) = x^2 - 5, you start with the graph of f(x)=x2f(x) = x^2 and shift it vertically down 5 units because k=5k = -5.

Section 2

Graph Quadratic Functions of the form f(x) = (x - h)^2

Property

The graph of f(x)=(xh)2f(x) = (x - h)^2 shifts the graph of f(x)=x2f(x) = x^2 horizontally hh units.

  • If h>0h > 0, shift the parabola horizontally right hh units.
  • If h<0h < 0, shift the parabola horizontally left h|h| units.

Examples

  • To graph f(x)=(x3)2f(x) = (x - 3)^2, you shift the graph of f(x)=x2f(x) = x^2 to the right 3 units. The vertex moves from (0,0)(0, 0) to (3,0)(3, 0).
  • To graph f(x)=(x+4)2f(x) = (x + 4)^2, you rewrite it as f(x)=(x(4))2f(x) = (x - (-4))^2. This means you shift the graph of f(x)=x2f(x) = x^2 to the left 4 units.

Book overview

Jump across lessons in the current chapter without opening the full course modal.

Continue this chapter

Chapter 4: Polynomial Functions

  1. Lesson 1

    Lesson 1: Graphing Polynomial Functions

  2. Lesson 2

    Lesson 2: Adding, Subtracting, and Multiplying Polynomials

  3. Lesson 3

    Lesson 3: Dividing Polynomials

  4. Lesson 4

    Lesson 4: Factoring Polynomials

  5. Lesson 5

    Lesson 5: Solving Polynomial Equations

  6. Lesson 6

    Lesson 6: The Fundamental Theorem of Algebra

  7. Lesson 7Current

    Lesson 7: Transformations of Polynomial Functions

  8. Lesson 8

    Lesson 8: Analyzing Graphs of Polynomial Functions

  9. Lesson 9

    Lesson 9: Modeling with Polynomial Functions