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1.6 
Graphical 
Transformations 
Copyright 息 2011 Pearson, Inc.
What youll learn about 
 Transformations 
 Vertical and Horizontal Translations 
 Reflections Across Axes 
 Vertical and Horizontal Stretches and Shrinks 
 Combining Transformations 
 and why 
Studying transformations will help you to understand 
the relationships between graphs that have similarities 
but are not the same. 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 2
Transformations 
In this section we relate graphs using 
transformations, which are functions that map 
real numbers to real numbers. 
Rigid transformations, which leave the size and 
shape of a graph unchanged, include horizontal 
translations, vertical translations, reflections, or 
any combination of these. 
Nonrigid transformations, which generally 
distort the shape of a graph, include horizontal or 
vertical stretches and shrinks. 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 3
Vertical and Horizontal Translations 
Let c be a positive real number. Then the following 
transformations result in translations of the graph of 
y = f(x). 
Horizontal Translations 
y = f(x  c) a translation to the right by c units 
y = f(x + c) a translation to the left by c units 
Vertical Translations 
y = f(x) + c a translation up by c units 
y = f(x)  c a translation down by c units 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 4
Example Vertical Translations 
Describe how the graph of f (x)  x can 
be transformed to the graph of y  x  4. 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 5
Solution 
Describe how the graph of f (x)  x can 
be transformed to the graph of y  x  4. 
It is a translation 
down by 4 units. 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 6
Example Finding Equations for 
Translations 
Each view shows the graph of y1  x3 and a vertical 
or horizontal translation y2 . Write an equation for y2 . 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 7
Solution 
Each view shows the graph of y1  x3 and a vertical 
or horizontal translation y2 . Write an equation for y2 . 
(a) y2  x3  3 (b) y2  x  23 
(c) y2  x  33 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 8
Reflections 
The following transformations result in 
reflections of the graph of y = f(x): 
Across the x-axis 
y = f(x) 
Across the y-axis 
y = f(x) 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 9
Graphing Absolute Value Compositions 
Given the graph of y = f(x), 
the graph y = |f(x)| can be obtained by reflecting 
the portion of the graph below the x-axis across the 
x-axis, leaving the portion above the x-axis 
unchanged; 
the graph of y = f(|x|) can be obtained by replacing 
the portion of the graph to the left of the y-axis by a 
reflection of the portion to the right of the y-axis 
across the y-axis, leaving the portion to the right of 
the y-axis unchanged. (The result will show even 
symmetry.) 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 10
Stretches and Shrinks 
Let c be a positive real number. Then the following 
transformations result in stretches or shrinks of the 
graph of y  f (x): 
Horizontal Stretches or Shrinks 
y  f 
x 
c 
 
  
 
  
a stretch by a factor of c if c  1 
a shrink by a factor of c if c  1 
 
 
 
Vertical Stretches or Shrinks 
y  c  f (x) 
a stretch by a factor of c if c  1 
a shrink by a factor of c if c  1 
 
 
 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 11
Example Finding Equations for 
Stretches and Shrinks 
Let C1 be the curve defined by y1  x3  3. Find equations 
for the following non-rigid transformations of C1 : 
(a) C2 is a vertical stretch of C1 by a factor of 4. 
(b) C3 is a horizontal shrink of C1 by a factor of 1/3. 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 12
Solution 
Let C1 be the curve defined by y1  x3  3. Find equations 
for the following non-rigid transformations of C1 : 
(a) C2 is a vertical stretch of C1 by a factor of 4. 
(b) C3 is a horizontal shrink of C1 by a factor of 1/3. 
(a) y2  4  f (x) 
 4(x3  3) 
 4x3  12 
(b) y3  f 
x 
1 / 3 
 
  
 
  
 f (3x) 
 (3x)3  3 
 27x3  3 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 13
Example Combining 
Transformations in Order 
The graph of y  x2 undergoes the following 
transformations, in order. 
Find the equation of the graph that results. 
 a horizontal shift 5 units to the left 
 a vertical stretch by a factor of 3 
 a vertical translation 4 units up 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 14
Solution 
The graph of y  x2 undergoes the following 
transformations, in order. 
Find the equation of the graph that results. 
 a horizontal shift 5 units to the left 
 a vertical stretch by a factor of 3 
 a vertical translation 4 units up 
x2 x  52 
3x  52 
3x  52 
 4 
Expanding the final expression: y  3x2  30x  79 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 15
Example Combining 
Transformations in Order 
Describe how to transform the graph of y  f x 
shown to the graph of y   f x  2 4. 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 16
Solution 
Describe how to transform the graph of y  f x 
shown to the graph of y   f x  2 4. 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 17
Solution (continued) 
Describe how to transform the graph of y  f x 
shown to the graph of y   f x  2 4. 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 18
Quick Review 
Write the expression as a binomial squared. 
1. x2  4x  4 
2. x2  2x  1 
3. 4x2  36x  81 
Perform the indicated operations and simplify. 
4. (x  1)2  (x  1)  2 
5. (x  1)3  (x  1)  2 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 19
Quick Review Solutions 
Write the expression as a binomial squared. 
1. x2  4x  4 (x  2)2 
2. x2  2x  1 (x  1)2 
3. 4x2  36x  81 (2x  9)2 
Perform the indicated operations and simplify. 
4. (x  1)2  (x  1)  2 x2  x  2 
5. (x  1)3  (x  1)  2 x3  3x2  4x 
Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 20

More Related Content

Unit 1.6

  • 1. 1.6 Graphical Transformations Copyright 息 2011 Pearson, Inc.
  • 2. What youll learn about Transformations Vertical and Horizontal Translations Reflections Across Axes Vertical and Horizontal Stretches and Shrinks Combining Transformations and why Studying transformations will help you to understand the relationships between graphs that have similarities but are not the same. Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 2
  • 3. Transformations In this section we relate graphs using transformations, which are functions that map real numbers to real numbers. Rigid transformations, which leave the size and shape of a graph unchanged, include horizontal translations, vertical translations, reflections, or any combination of these. Nonrigid transformations, which generally distort the shape of a graph, include horizontal or vertical stretches and shrinks. Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 3
  • 4. Vertical and Horizontal Translations Let c be a positive real number. Then the following transformations result in translations of the graph of y = f(x). Horizontal Translations y = f(x c) a translation to the right by c units y = f(x + c) a translation to the left by c units Vertical Translations y = f(x) + c a translation up by c units y = f(x) c a translation down by c units Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 4
  • 5. Example Vertical Translations Describe how the graph of f (x) x can be transformed to the graph of y x 4. Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 5
  • 6. Solution Describe how the graph of f (x) x can be transformed to the graph of y x 4. It is a translation down by 4 units. Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 6
  • 7. Example Finding Equations for Translations Each view shows the graph of y1 x3 and a vertical or horizontal translation y2 . Write an equation for y2 . Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 7
  • 8. Solution Each view shows the graph of y1 x3 and a vertical or horizontal translation y2 . Write an equation for y2 . (a) y2 x3 3 (b) y2 x 23 (c) y2 x 33 Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 8
  • 9. Reflections The following transformations result in reflections of the graph of y = f(x): Across the x-axis y = f(x) Across the y-axis y = f(x) Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 9
  • 10. Graphing Absolute Value Compositions Given the graph of y = f(x), the graph y = |f(x)| can be obtained by reflecting the portion of the graph below the x-axis across the x-axis, leaving the portion above the x-axis unchanged; the graph of y = f(|x|) can be obtained by replacing the portion of the graph to the left of the y-axis by a reflection of the portion to the right of the y-axis across the y-axis, leaving the portion to the right of the y-axis unchanged. (The result will show even symmetry.) Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 10
  • 11. Stretches and Shrinks Let c be a positive real number. Then the following transformations result in stretches or shrinks of the graph of y f (x): Horizontal Stretches or Shrinks y f x c a stretch by a factor of c if c 1 a shrink by a factor of c if c 1 Vertical Stretches or Shrinks y c f (x) a stretch by a factor of c if c 1 a shrink by a factor of c if c 1 Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 11
  • 12. Example Finding Equations for Stretches and Shrinks Let C1 be the curve defined by y1 x3 3. Find equations for the following non-rigid transformations of C1 : (a) C2 is a vertical stretch of C1 by a factor of 4. (b) C3 is a horizontal shrink of C1 by a factor of 1/3. Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 12
  • 13. Solution Let C1 be the curve defined by y1 x3 3. Find equations for the following non-rigid transformations of C1 : (a) C2 is a vertical stretch of C1 by a factor of 4. (b) C3 is a horizontal shrink of C1 by a factor of 1/3. (a) y2 4 f (x) 4(x3 3) 4x3 12 (b) y3 f x 1 / 3 f (3x) (3x)3 3 27x3 3 Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 13
  • 14. Example Combining Transformations in Order The graph of y x2 undergoes the following transformations, in order. Find the equation of the graph that results. a horizontal shift 5 units to the left a vertical stretch by a factor of 3 a vertical translation 4 units up Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 14
  • 15. Solution The graph of y x2 undergoes the following transformations, in order. Find the equation of the graph that results. a horizontal shift 5 units to the left a vertical stretch by a factor of 3 a vertical translation 4 units up x2 x 52 3x 52 3x 52 4 Expanding the final expression: y 3x2 30x 79 Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 15
  • 16. Example Combining Transformations in Order Describe how to transform the graph of y f x shown to the graph of y f x 2 4. Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 16
  • 17. Solution Describe how to transform the graph of y f x shown to the graph of y f x 2 4. Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 17
  • 18. Solution (continued) Describe how to transform the graph of y f x shown to the graph of y f x 2 4. Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 18
  • 19. Quick Review Write the expression as a binomial squared. 1. x2 4x 4 2. x2 2x 1 3. 4x2 36x 81 Perform the indicated operations and simplify. 4. (x 1)2 (x 1) 2 5. (x 1)3 (x 1) 2 Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 19
  • 20. Quick Review Solutions Write the expression as a binomial squared. 1. x2 4x 4 (x 2)2 2. x2 2x 1 (x 1)2 3. 4x2 36x 81 (2x 9)2 Perform the indicated operations and simplify. 4. (x 1)2 (x 1) 2 x2 x 2 5. (x 1)3 (x 1) 2 x3 3x2 4x Copyright 息 2011 Pearson, Inc. 際際滷 1.6 - 20