This preview shows pages 1–3. Sign up to view the full content.
Math 1310 Class Notes – Section 3.3, Page 1 of 4
Math 1310
Section 3.3
Variation
You’ll be asked to solve some problems involving functions using
variation.
We’ll
consider three types of variation.
•
Variation formulas
Direct variation
:
We say
y
varies directly as
x
, or
y
is directly proportional to
x
, if
,
kx
y
=
where
k
is a constant
( 29
.
0
≠
k
Inverse variation
:
We say
y
varies inversely as
x
, or
y
is inversely proportional to
x
, if
,
x
k
y
=
where
k
is a constant
( 29
.
0
≠
k
Joint variation
:
We way
y
varies jointly as
x
and
z
, or
y
is jointly proportional to
x
and
z
,
if
,
kxz
y
=
where
k
is a constant
( 29
.
0
≠
k
In each instance above,
k
is called the constant of proportionality.
You’ll be asked to find one (or more) of three things:
•
a formula that corresponds to a given statement
•
the constant of proportionality,
k
•
a value for one variable, given other values
Example 1:
Suppose
y
is directly proportional to
x
and
4
=
x
when
6
=
y
.
Write a
formula to express the given statement and find the constant of proportionality.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentMath 1310 Class Notes – Section 3.3, Page 2 of 4
This is the end of the preview. Sign up
to
access the rest of the document.
 Summer '08
 MARKS
 Direct Variation, Inverse Variation, Formulas

Click to edit the document details