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Enrichment:
Graphing with Absolute Values
Objective To make a table of integer values of xfor graphing absolute-value functions
and to describe how the graphs change as the functions vary
You have found absolute values of numbers and simplified absolute value
expressions. Now you will extend your understanding of absolute value to
graph absolute-value functions.
The graphs of absolute-value functions are all related to the graph of the
absolute-value function: f(x) |x|. The f(x) notation is another way to
represent the y-values of x.
To graph f(x) |x|, first make a table of values.
You may use the values in the table below or
choose others.
Plot the values from your table. Use the f(x) values as the
y-coordinates. Then connect the points. The graph below uses
the table of values above.
Because |x| is always greater than or equal to zero for all values of x,
there are no points in Quadrant III or IV. Notice that the part of the
graph in Quadrant II is the reflection image of the part of the graph
in Quadrant I. This is because |x| |x| for any number x. That is,
the absolute value of a number is the same as the absolute value of
its opposite.
f(x) |x|
Input
x
Output
f(x)
4 |4| 4
2 |2| 2
0 |0| 0
2|2| 2
4|4| 4
y
x
4XDGUDQWII 4XDGUDQWI
4XDGUDQWIII 4XDGUDQWIV
f(x) |x|