Big Ideas Math Algebra 1, 2015
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Big Ideas Math Algebra 1, 2015 View details
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Exercise 10 Page 169

Make a table of values to find points on the graph. Think about the horizontal transformations before thinking about any vertical transformations. Work from the inside to the outside.

Graph:

answer_graphs

Transformations:
Horizontal translation 2 units to the left.
Horizontal shrink by a factor of 12.

Practice makes perfect

First, we will make a table of values to graph these functions. After that, we will go through all the transformations from the graph of f(x)=|x| to the graph of g(x)=|2x+4|.

Graphs

Let's make a table of values for each of the functions. After that, we will plot the ordered pairs that we find and connect them. Let's start with f(x).

x |x| f(x)
-4 | -4| 4
-2 | -2| 2
0 | 0| 0
2 | 2| 2
4 | 4| 4
Now, let's make a table for g(x)
x |2x+4| g(x)
-4 |2( -4)+4| 4
-3 |2( -3)+4| 2
-2 |2( -2)+4| 0
-1 |2( -1)+4| 2
0 |2( 0)+4| 4

Let's plot the points of each function and connect them. We will do this in the same coordinate plane.

functions_graph

Transformations

We wil look at each of the transformations individually and work our way from the inside to the outside. g(x)=|2x+4| The given equation is a transformation of the parent function f(x)=|x|. To see how each of the parameters is affecting the parent function, it will be helpful to rewrite it first. g(x)&=|2x+4| &⇕ g(x)&=|2(x+2)| We will start with the transformation closest to x and end with the farthest from x. First, there is a horizontal translation 2 units to the left. |x|⇒|x+ 2| Remember, typically |x-h| is a horizontal translation h units to the right, while |x+h| is translated h units to the left.

horizontal_translation

Next, we have a horizontal shrink by a factor of 12. This transforms the graph of y=|x+2| to the graph of y=|2x+4|.

horizontal_shrink