Algebra
Lesson 4-6
Functions
Vocabulary:
- Function-a relation where each element that is part of the domain is paired with exactly one element of the range.
- Vertical Line Test-This is a test to see if a graph is a function or not. You take a vertical line such as a pencil or pen, and slide it across the graph. If at any point your vertical line touches two or more points at once, then it is not a function.
- Function Notation-A way to write equations that are functions. (Example: y= 4x-7 becomes f(x)=4x-7)
Examples:
Example #1
Is this a function?
Example #2
Determine if these are functions:
a.
b.x|y
3|4
-2|1
4|6
-2|5
1|1
c.
Answers:
a. It is a function. If you test with the vertical line test you see that the line of points is never touching your vertical line in two or more places at once.
b.It is not a function because there are repeating X values.
c.It is not a function. If you test with the vertical line test you see that your vertical line touches the line of points in two places at once.
Example #3
If m(x)=x(3-1)+2-x, then find this value.
m(4)+2
First fill in the equation:
m(x)=4(3-1)+2-4
m(x)=4(2)+2-4
m(x)=8+2-4
m(x)=10-4
m(x)=6
You still have to add the 2 at the end though.
So m(x)=6+2
Answer: m(x)=8
Additional Information:
Online resources:
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