alg2 1.3 notes.notebook - bainbridge island school … 1.3 notes.notebook september 05, 2012 1 3...
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Alg2 1.3 Notes.notebook September 05, 2012
Give the coordinates of each transformation of (2, –3).
1. horizontal translation of 5
2. vertical translation of –1
3. reflection across the xaxis
4. reflection across the yaxis
5. f(x) = 3(x + 5) – 1 6. f(x) = x2 + 4x
Evaluate f(–2) and f(1.5).
Alg2 1.3 Notes.notebook September 05, 2012
13 Transforming Linear Functions
Transform linear functions by shifting, reflecting, and stretching/compressing.
Solve problems involving linear transformations.
Transformations allow you to visualize and compare many different functions at once.
Translations
To remember the difference between vertical and horizontal translations, think:
“Add to y, go high.”
“Add to x, go left.”
Alg2 1.3 Notes.notebook September 05, 2012
f(x) = x + 3
Is this a vertical shift or a horizontal shift?
Let g(x) be the indicated transformation of f(x).
Write the rule for g(x).
Translating f(x) 3 units right subtracts 3 from each input value.
I. Translating Linear Functions
1) f(x) = 3x + 2, horizontal translation right 3 units
2) f(x) = 6x 5, vertical translation down 3 units
Alg2 1.3 Notes.notebook September 05, 2012
Reflections
II. Reflecting Linear Functions
Let g(x) be the indicated transformation of f(x).
Write the rule for g(x).
3) f(x) = 2x + 5, reflected across the xaxis
4) f(x) = 2x + 5, reflected across the yaxis
Alg2 1.3 Notes.notebook September 05, 2012
Step 2 Write the rule for g(x). Reflecting f(x) across the
xaxis replaces each y with –y.
III. Transformation of Linear Functions Defined by a Table
Let g(x) be the indicated transformation of f(x), defined in the table below. Write the rule for g(x).
x -1 0 1f(x) 1 2 3
5) Reflection across the xaxis
III. Transformation of Linear Functions Defined by a Table
6) Reflection across xaxis
Let g(x) be the indicated transformation of f(x), defined in the table below. Write the rule for g(x).
x 2 0 2f(x) 0 1 2
7) Reflection across yaxis
Alg2 1.3 Notes.notebook September 05, 2012
Stretches and Compressions
These don’t change!
y–intercepts in a horizontal stretch or compression
x–intercepts in a vertical stretch or compression
Alg2 1.3 Notes.notebook September 05, 2012
Horizontally compressing f(x) by a factor of replaces each x
with where b = .
IV. Stretching and Compressing Linear Functions
8) Let g(x) be a horizontal compression of f(x) = x + 4 by a factor of . Write the rule for g(x), and graph the function.
What if you wanted to do a horizontal shift of f(x) = 3x left 6 units followed by a horizontal stretch by a factor of 4?
1st: translate, 2nd: stretch
Alg2 1.3 Notes.notebook September 05, 2012
The Dance Club is selling beaded purses as a fundraiser. The function R(n) = 12.5n represents the club’s revenue in dollars where n is the number of purses sold.
The club paid $75 for the materials needed to make the purses. Write a new function P(n) for the club’s profit.
1. What if …? The club members decided to double the price of each purse
IV. Application
2. Graph both S(n) and P(n) on the same coordinate plane.
3. Describe the transformation(s) that have been applied.