constant of proportionality. a direct variation is represented by a ratio or equation : or k ≠ 0...
Post on 22-Dec-2015
212 Views
Preview:
TRANSCRIPT
Constant of Proportionality
A direct variation is represented by a ratio or equation :
kx
y or kxy k ≠ 0
Direct Variation – constant ratio
EX1)
x 1 2 3 4y 3 6 9 12
Determine if the table represents a direct variation. If so, state the constant of proportionality
Step 1 Substitute values for variables
1
3
x
y
K =
2
6
3
9
4
12
3 3 3 3
Step 2 Simplify
This is a direct variation because the ratios are constant. The constant of proportionality is 3.
EX2) Identify the constant of proportionality in the equation y=15x where
y = 15 x
k = constant of proportionalityy = k x
15 = constant of proportionality
Explain the relationship. y = cost of concert tickets and x = number of concert tickets
Each concert ticket cost $15.
EX3) Refer to the graph. Is there a direct variation? Explain
0 1 2 30
2
4
6
8
pounds
$
There is not a direct variation.
The line does not go through the origin.
notes
Constant of Proportionality
Date ____________
A direct variation is represented by a ratio or equation :
Direct Variation –
EX1)
xy
Determine if the table represents a direct variation.
Step 1
Step 2
EX2) Identify the constant of proportionality.
y = 15 x
k =
Explain the relationship.
y =
x =
EX3) Refer to the graph. Is there a direct variation? Explain
0 1 2 30
2
4
6
8
pounds
$
top related