Piecewise Functions
Absolute Value Funtions
Prepared by:
Ms. Shiela Salvador
Piecewise Defined Functions
• In preparation for the definition of the
absolute value function, it is extremely
important to have a good grasp of the concept
of a piecewise defined function.
• Definition: A piecewise function is a function
defined by two or more equations. Each
“piece” of the function applies to a different
part of its domain.
Evaluating Piecewise Functions
To evaluate a piecewise function, identify or figure out
which piece applies to the given value of
Consider the function
Evaluate the following:
1. 6.
2. 7.
3. 8.
4. 9.
5. 10.
Domain of a Piecewise Function
• To determine the domain of a piecewise function is
simply to inspect where the given pieces are defined.
Determine the domain of each piecewise function.
Notice that is defined for all less than or equal to While is
defined for all greater than . This means that the function is
defined for all possible values of .
Domain: set of real numbers
2.
Domain:
Graphing Piecewise Functions
• In graphing a piecewise function, we can follow the
following steps:
1. Evaluate the endpoint(s) of function
2. Plot a few more points to give the shape
3. Repeat for each piece
Graphing Piecewise Functions
Graph the following piecewise functions and identify its
domain and range.
Example 1.
At At
Endpoint
At
– hole
Graph is a horizontal line.
Endpoint
At
– included
Additional points:
At
At
Graphing Piecewise Functions
• Graph of
Domain: set of real numbers
Range:
Graphing Piecewise Functions
Example 2.
At At At
Endpoint
If ,
- hole
Additional Points:
If ,
If ,
Endpoints
If ,
- hole
If ,
- hole
No need for
additional points.
Endpoint
If ,
- included
Additional Points:
If ,
If ,
Graphing Piecewise Functions
• Graph of
Domain:
Range: all real numbers
Graphing Piecewise Functions
Example 3.
At At At
Endpoint
If ,
- included
Additional Points:
If ,
If ,
Endpoints
If ,
- hole
If ,
- included
No need for
additional points
Parabola opening
upward with vertex
at y=-2x
Endpoint
If ,
- hole
Additional Points:
If ,
Graphing Piecewise Functions
• Graph of
Domain: all real numbers
Range:
The Absolute Value Function
• An absolute value function is a function that contains
an absolute value expression. The can be written as
a piecewise function:
• Hence the graph is
• Domain: set of real numbers
• Range:
Graphing Absolute Value Functions
The graph of has the following characteristics.
• The graph has vertex and is symmetric in the line .
• The graph is V-shaped. It opens up if and down if .
• The graph is wider than the graph of if
• The graph is narrower than the graph of if .
Graphing Absolute Value Functions
Examples. Graph the following absolute value functions
and determine its domain and range.
Example 1.
Vertex:
Opening upward
Symmetric at
Domain: all real numbers
Range:
Graphing Absolute Value Functions
Example 2:
Vertex:
Opening downward
Symmetric at
Domain: all real numbers
Range:
Graphing Absolute Value Functions
Example 3.
Vertex:
Opening upward
Symmetric at
Domain: all real numbers
Range:
Practice Exercises
• Sketch the graph of the following functions.
Determine the domain and range. Show and
indicated pertinent details.
http://
msenux2.redwoods.edu/IntAlgText/chapter4/section1.pdf
http://
www.kkuniyuk.com/PrecalcBook/Precalc0105to0107.pdf
https://
www.cusd80.com/cms/lib/AZ01001175/Centricity/Domain/2
385/4.7%20Alg.pdf
https://
wl.apsva.us/wp-content/uploads/sites/38/2017/08/Wright-2.7-
Piecewise-SY18.pdf
https://
www.jacksonsd.org/cms/lib/NJ01912744/Centricity/Domain/
504/Alg%203.7%20BI%20TB.pdf

Piecewise and absolute Value Functions.pptx