Warm ups
Where does the graph of y = 2x – 8 intersect the
x-axis?
(4,0)
Find the slope between (-2,5) & (-2,7)
Undefined.
Find the root/solution of 3x – 15 = y
5
3-6 PROPORTIONAL AND
NONPROPORTIONAL
RELATIONSHIPS
Objective: Write an equation for a proportional
relationship. Write a relationship for a
nonproportional relationship.
Concept
Example 1 A
A. ENERGY The table shows
the number of miles driven
for each hour of driving.
Graph the data. What can you deduce from the
pattern about the relationship between the number
of hours of driving h and the numbers of miles
driven m?
Answer: There is a linear
relationship between
hours of driving and the
number of miles driven.
Proportional Relationships
Example 1 B
B. Write an equation to describe this relationship.
Look at the relationship between the domain and the
range to find a pattern that can be described as
an equation.
Answer: m = 50h
Proportional Relationships
Try with a Mathlete
Write an equation to
describe the relationship
between hours and miles
walked.
A. m = 3h
B. m = 2h
C. m = 1.5h
D. m = 1h
Example 2 (nonproportional)
Find a function that represents the relationship shown
x
1
2
3
4
y
9
12
15
18
f (x) = 3x + 6
Nonproportional Relationships
Example 3
Find a function that represents the relationship shown
x
1
2
3
4
y
3
2
1
0
f (x) = -x + 4
Nonproportional Relationships
Example 4
Find a function that represents the relationship shown
x
1
2
3
4
y
3
5
7
9
f (x) = 2x +1
Nonproportional Relationships
TOO
Write an equation in function notation for the relation
that is graphed.
A.
f(x) = x + 2
B.
f(x) = 2x
C.
f(x) = 2x + 2
D.
f(x) = 2x + 1
Homework
• 3-6 Worksheet