Inverse and Direct Variation from Sue.notebook
December 04, 2015
The variables x and y vary inversely. Write and equation that relates the variables.
x = 2, y = 4
x = 1/2, y = 6
x = 3, y = .01
Inverse 1
1
Inverse and Direct Variation from Sue.notebook
December 04, 2015
Boyle’s Law states that for a constant temperature, the pressure, P, of a gas varies inversely with its volume, V. A sample of hydrogen gas has a volume of 8.56 liters at a pressure of 1.5 atmospheres.
First, find the constant of variation, k. Second, write an equation that relates P and V. Last, find the volume of the hydrogen gas if the temperature remains constant and the pressure changes to 1.2 atmospheres.
Inverse 2
2
Inverse and Direct Variation from Sue.notebook
December 04, 2015
The amount of time necessary to make a trip varies inversely as the rate of travel. At 40 miles per hour it takes Valerie 5 hours to reach her destination. First, find the constant of variation, k. Second, write an equation that relates the variables. Last, find how long it would take if she drove at 50 miles per hour.
Inverse 3
3
Inverse and Direct Variation from Sue.notebook
December 04, 2015
The current in an electrical circuit varies inversely as the amount of resistance in the circuit. The current is 10 amps when the resistance is 24 ohms. Find the current when the resistance is 30 ohms.
Inverse 4
4
Inverse and Direct Variation from Sue.notebook
December 04, 2015
Determining the type of Variation given a table
Type:
Direct
Inverse
Remember:
Find k for
each pair
of x and y.
They must
all be the
same to
be
variation.
X
Y
X
Y
5
55
2
35
6
66
7
10
7
77
10
7
Using Tables
5
Inverse and Direct Variation from Sue.notebook
December 04, 2015
Practice with tables:
X
Y
X
Y
X
Y
3
16
2
9
2
5
6
8
8
36
4
9
24
2
16
72
6
13
tables practice
6
Inverse and Direct Variation from Sue.notebook
December 04, 2015
The points (2,3), (4, 3/4), and (6,d) lie on the graph of a
function.
If y is inversely proportional to the square of x, what is
the value of d?
(1)
(2)
(3)
(4)
1
1/3
3
27
Dec 5­10:09 AM
7