# Direct Variation

• Dec 29th 2008, 02:35 PM
Russian
Direct Variation
First of all, I am new ,so hello.

now to the topic:
is the formula for direct variation y=kx
and could you please post examples?
• Dec 29th 2008, 02:39 PM
masters
Quote:

Originally Posted by Russian
First of all, I am new ,so hello.

now to the topic:
is the formula for direct variation y=kx
and could you please post examples?

This is correct. y varies directly as x.

k is called the constant of proportionality or the constant of variation.

• Dec 29th 2008, 02:49 PM
Russian
Quote:

Originally Posted by masters
This is correct. y varies directly as x.

k is called the constant of proportionality or the constant of variation.

so you use the formula and then plug the answer as k?
• Dec 30th 2008, 05:43 AM
masters
Quote:

Originally Posted by Russian
so you use the formula and then plug the answer as k?

Example: d = rt (distance = rate X time)

Let r be the constant of variation.

The distance (d) varies directly as time (t) if r remains constant. In other words, when t increases, d increases. When t decreases, d decreases.

Follow some of the links I gave you and you'll see other examples.

Also, investigate inverse and joint variation as well.
• Jan 1st 2009, 03:26 PM
Russian
Quote:

Originally Posted by masters
Example: d = rt (distance = rate X time)

Let r be the constant of variation.

The distance (d) varies directly as time (t) if r remains constant. In other words, when t increases, d increases. When t decreases, d decreases.

Follow some of the links I gave you and you'll see other examples.

Also, investigate inverse and joint variation as well.

thank you, masters