Unit 5: Lesson Four- Evaluating Polynomial Functions
Recall:

Function Notation: f x  means the same thing as y. So, f ( 2) just means the value of y when x=2.

Ordered Pairs:
x, y  means the same thing
as x, f x
Note:

In your book, they will ask you to verify your answer using “technology” or a “graphing calculator.”
Ignore those instructions and just use your calculator.
Example: f x   3x 3  2 x 2  x  7 . Find the value of this function for each of the following values.
a) x=1
b) x=-2
f 1  31  21  1  7
 3  2 1 7
 5
3
2
f  2   3 2   2 2   2   7
 3 8  24   2  7
 24  8  2  7
 41
3
2
Example: Evaluate each of the following functions for x=3. Round to two decimal places, if required.
a) f  x  
2x  1
f 3  23  1
 5
c) f  x  
f 3 
1
x2
1
32
1
1
1

Hw. P. 95-97 #1ade, 2ab, 3a,4b, 5ab, 6ef7ai,iv, 9bc,14
b) f x   2 x
f 3  2 3
8
d) f x   4
Since this is a “constant”
function, the value for
f(x), or y, is ALWAYS 4.
 f 3  4