Functions, Equations,
and Graphs
Ch. 2.1
Relations and Functions
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Bell Work
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Random Announcements…
Seating Chart
Data
Grading
CW- 40%
Quiz/Test- 40%
Homework- 10%
Notebook Check- 10%
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Relations and Functions
READ
A relation is a set of ordered pairs. Some
relations meet a special condition that makes them
functions. In a functions each item from the domain
pairs with exactly one item from the range. A
relations is identified as a function if
 its graph passes the vertical line test
 its domain values appear only once (in a list of
ordered pairs, in a table, or on a mapping
diagram), or
 its mapping diagram maps each input to only
one output. (This means only one arrow can be
drawn from each input value.)
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Relations and Functions
 https://www.khanacademy.org/math/cc-eighthgrade-math/cc-8th-linear-equations-functions/cc-8thfunction-intro/v/relations-and-functions
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Relations
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Representing a Relation
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Representing a Function
Now you try…
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Finding Domain and Range
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Finding domain and range
Now you try…
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Identifying a function
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Identifying a function
Now you try…
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Vertical-Line test
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Vertical-Line Test
Now you try…
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Need to know…
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Function Notation
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Function Notation
Now you try…
For f(x)=-4x + 1, what is the output for the given input?
a.
-2
b.
0
c.
5
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.
Closure
(On your bell sheet)
EQ: How can I determine if a relation is a function? I will describe what makes a relation a function.