pc notes c1s2.notebook
September 09, 2014
Ch. 1 Sec. 2
Functions
Function ­ a relationship between two variables that takes each independent (x) variable and matches it to exactly one dependent (y)
value.
•
•
•
•
each x must be matched to one y­value,
some values of y may not be matched to a value of x,
different values of x can have the same values of y,
the same x­value cannot be matched to different y­values.
examples on pg 4
1
pc notes c1s2.notebook
Example
September 09, 2014
Do these represent functions?
x
y
2
4
4
­5
­3
4
0
0
­7
1
2
pc notes c1s2.notebook
September 09, 2014
Function Notation
f is the name of the function
x is the independent value (input)
y is the dependent value (output)
is the value of the function at a specific x value
Example
Find
Find and
and
when
when
3
pc notes c1s2.notebook
September 09, 2014
Restrictions of Functions Domain ­ the set of values for x for which the function is defined. (possible values of x)
Range ­ the set of values the function takes on. (possible y values)
Example
4
pc notes c1s2.notebook
September 09, 2014
Example
Find the domain for the following functions.
f(x)=3x+8
5