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Chapter 1 . 1-4 Shifting, reflecting and stretching graphs. objectives. The student will be able to: Recognize graphs of parent functions Use vertical and horizontal shifts and reflections to graph functions Use nonrigid transformations. Parent functions. What are parent functions?
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Chapter 1 1-4 Shifting, reflecting and stretching graphs
objectives • The student will be able to: • Recognize graphs of parent functions • Use vertical and horizontal shifts and reflections to graph functions • Use nonrigid transformations
Parent functions • What are parent functions? • Answer: A parent function is the simplest function with the defining characteristic of the family. Functions in the same family are transformations of the parent functions.
Vertical and horizontal shift • Let c be a positive real number. Vertical and horizontal shifts in the graph of are represented as follows: • Vertical shifts c units upward: • Vertical shift c units downward: • Horizontal shift c units to the right: • Horizontal shift c units to the left:
Example 1 • Many functions have graphs that are simple transformations of the graphs of parent functions. • Example 1: • Sketch the graph of and .
Example 1 continue • If we graph . • What happen to the original graph? • It translate the original graph one unit up. This is what we called a vertical shift or vertical translation.
Example 2 • Example 2: • Sketch the graph of and .
Example 2 continue • If we graph . • What happen to the original graph? • It translate the original graph one unit to the right. This is what we called a Horizontalshiftor vertical translation.
Shifts in the graphs of a function • Lets compare the graph of each function to the parent function and describe the transformation. • A) • Shifting 8 units downs • B) • Shifting 5 units to the right • C) • Shifting 4 units up
Student Practice • Do problems 7 and 8 from book page 47
Finding equations from graphs Example #3 Each graph is a transformation of the graph f. . Find the equation of the graphs
Student Guided practice • Lets do problems 30 and 32 from page 48
Reflecting Graphs • Another type of transformation is called reflection. • There are two types of reflection across the coordinate axis: • Reflection in the x-axis h(x)=-f(x) • Reflection in the y-axis h(x)=f(-x)
Example 4 Lets look at our normal quadratic function
Example 4 continue • What happen when we add a negative to the • So now we have This is what we called reflection across the x-axis
Example 5 • Now lets change x in the • So now we have • Since is the same line that is what we called reflection across the y-axis
Student Guided practice Work on reflection worksheet
Example 6 Lets compare the following equations to the equation
NONRIGID TRANSFORMATION What are rigid transformations?Answer: horizontal shifts, vertical shifts, and reflections are called rigid transformations. These transformations change only the position of the graph in the coordinate plane. What are nonrigid transformations? Answer: Are those that cause a distortion- a change in the shape of the original graph. Like vertical and horizontal stretches and compressions.
NonRigid transformations types • For y = f(x) and the real number c, • • A vertical stretch is represented by g(x) = cf(x) , • where c > 1 . • • A vertical shrink is represented by g(x) = cf(x) , • where 0 < c < 1 . • • A horizontal shrink is represented by h(x) = f(cx) , • where c > 1 . • • A horizontal stretch is represented by h(x) = f(cx) , where 0 < c < 1 .
Homework • Do problems 10-12 ,35-46 odd numbers • From pages 47 and 48.
Closure • Today we learned about transformations of functions and rigid and nonrigid transformations.