October 07, 2014
Lesson 1.6: Graphing Relations
Focus: Create a table of values, then graph.
GETTING STARTED:
Look at the graph at the top of p. 30.
What does this graph show?
What do the numbers along the horizontal
axis show?
What do the numbers along the vertical axis show?
How many jellybeans does one grid square on the vertical axis represent?
1. Look at point (2, 60)
a) What does this point tell us about the
number of jellybeans?
b) How many jellybeans do you think are in
each bag?
c) Why do you think so?
d) How would we write a relation to
represent this information?
October 07, 2014
e) How could we use the graph to find how many jellybeans are in
5 bags?
f) When we draw a graph, what do we need to include?
i)
ii)
iii)
iv)
EXPLORE: p. 30
The cost of n CDs, in dollars, is 12n
i) What is the cost of one CD?
ii) Complete the table below.
NUMBER OF
CDS
n
0
2
4
6
8
10
COST ($)
12n
How did you find the cost of 2 CDs?
October 07, 2014
Graph the data.
What label did you put on the
horizontal axis?
On the vertical axis?
How did you graph the data?
What scale did you use on
the horizontal axis?
On the vertical axis?
How did you find the cost of 5 CD's
How could you use the graph to get this information?
What patterns do you see in the table?
October 07, 2014
· How would you describe your graph?
· How do you get from one point to the next point on the graph?
· How can you describe this movement using the scales on the axes?
· How could you use the graph to find the cost of 12 CDs?
· How could you use the graph to find how many CDs you could buy
with $72?
Notes:
When graphing
Input is plotted on the ___________________
Output is plotted on the ___________________
When points can be connected by a straight line we say it is a
______________________
October 07, 2014
Example:
Mr. Beach has 25 granola bars. He gives 3 granola bars to each
student who stays after school to help prepare for the school
concert.
a) Write a relation to show how the number of granola bars that
remain is related to the number of helpers.
b) Make a table to show this relation.
NUMBER OF
HELPERS
NUMBER OF GRANOLA
BARS LEFT
n
c) Graph the data. Describe the graph.
d) Use the graph to answer
these questions...
i) How many granola bars
remain when 7 students
help?
ii)When will Mr. Beach
not have enough granola
bars?
October 07, 2014
Assignment:
p. 33 # 1, 2(graph only 1a and 1b), 4, 5, 6