5-1+5-2
What are three ways to make a statement about a variable?
You can use an equation, inequality, or a proportion.
The table identifies the x and y values; the graph gives a visual.
How can you write a function rule?
You can write a function rule by analyzing a table of values.
What is a Direct Variation?
A direct variation is y=kx, k doesn't equal 0.
What can you use to show the relationship of two variables?
A Graph
What is Discrete Data?
Data that involves a count of items; cars, people, etc.
Write a function rule for the table:
x y
1 3
2 6
3 9
4 12
f(x)=3x
What is the constant of variation?
K.
What is a Relation?
What is Continuous Data?
Data where numbers between any two values have meanings (connect the dots)
Write a function rule for the situation.
The total cost t(c) of c ounces of cinnamon if each ounce costs $.79.
t(c)=0.79c
Is the statement 2y=5x+1 a direct variation?
No.
What is a function?
A relation that assigns exactly one output (range) value for each input (domain) value.
Model the rule with a table:
f(x)=-3x
x y
6 -18
7 -21
8 -24
(answers may vary)
A worker's earnings e(n) for n hours when the worker's hourly wage is $6.37
e(n)=6.37n
Is the statement -12x=6y a direct variation?
Yes.
Decide wether this table is a function:
x y
11 -2
12 -1
13 7
20 7
This table is a function because there is no repeating domain.
Model the rule with a table:
f(x)=-2x-7
x y
1 -5
2 -3
3 -1
Write a rule to describe the function:
In 2002, the price of mailing a letter was $.34 for the first ounce or part of an ounce and $.21 for each ounce or part of an ounce after the first ounce.
f(x)=0.34+0.21(x-1)
Is the statement -x=10y a direct variation?
No.