CUBE ROOTS 12_4.notebook
1
December 07, 2017
Relations and
FunctionsWarning: There is lots of writing today! But before we start let's watch a video.. Do not write any notes from the video. They will follow in the slides after the video.
https://www.youtube.com/watch?v=wXAChECZf-o
*Please copy the link into an internet browser, make sure sound is on.. Thank you! A student can help if needed :)
(Copy this link into a browser!)
A relation is a set of ordered pairs. Ex: {(3, 4), (4, 16), (0, 5)}
domain (input) the set of xcoordinates in a relation
range (output) the set of ycoordinates in a relation
domain
range
write everything
CUBE ROOTS 12_4.notebook
2
December 07, 2017
Determine the domain and range of each relation.
1. {(0, -5), (0, 5), (3, -4), (3, 4)}Domain: ________________Range: _________________
2. {(-5, 0), (-4, 3), (-3, 4), (0, 5)}Domain: _________________Range: __________________
{0, 3}domain
domain
{0, 3, 4, 5}range
range
don't need to write
A function is a special relation such that for all values of x there exists one and only one yvalue. (xcoordinates are all different)
Are the following relations functions?
1. {(0, -5), (0, 5), (3, -4), (3, 4)}
2. {(-5, 0), (-4, 3), (-3, 4), (0, 5)}
No, xvalues repeatpull
pull Yes, xcoordinates
are all different
write everything
CUBE ROOTS 12_4.notebook
3
December 07, 2017
Vertical line test when given a graph, a vertical line drawn anywhere on the graph can only pass through one point to be a function.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0
1
2
3
4
5
6
90°
Function passes vertical line test
Not a function vertical line passes through more than 1 point
write everything
CUBE ROOTS 12_4.notebook
4
December 07, 2017
Are the following functions? How do you know?
don't need to write
domain range
Mapping a function To be a function, there can only be one arrow coming from each xcoordinate in the domain
This is not a function because there are 2 arrows coming from both the 0 and the 3 {(0, 2), (0, 2), (3,1),(3, 1)} in the domain (it does not matter if the range repeats)
write what's in black
CUBE ROOTS 12_4.notebook
5
December 07, 2017
CUBE ROOTS 12_4.notebook
6
December 07, 2017
Another way to write y = 3x + 4 as a function is f(x) = 3x + 4 also knows as function notation.
• f(x) or y are the same and they represent the range
• It is just an equation that passes the vertical line test when graphed
write everything
Evaluating a function simply substitute the given number in the function (equation)
Ex: Evaluate f(x) = 4x + 12 for x = 3 4(3) + 12
12 + 12
0
write everything
CUBE ROOTS 12_4.notebook
7
December 07, 2017
Finding the Range
Evaluate the function f(a) = 3a + 5 to find the range of the function for the domain {3, 1, 4}
{14, 2, 7) or {7, 2, 14}pull
do this, but you don't need to write everything
CUBE ROOTS 12_4.notebook
8
December 07, 2017
Homework: Worksheet (front and back)