Direct Variation

A direct variation is a linear function defined by an equation of the form y=kx, k0. You can say that y is directly proportional to x.
When two variable quantities have a constant ratio, their relationship is called direct variation. The constant ratio is called variation constant. You can write an equation to show the relationship.
Post	d	h	h/d	Now calculate the ratio (or direct variation) of height to distance.
1	2	1.5	.75
2	4	3	?
3	?	4.5	?
4	?	6	?
5	?	7.5	?
The equation h/d = .75 can also be written *h = .75d*.

Post	d	h	h/d	Now with the the simple ratio (h/d) to calculate the distance and notice that the variation constant is .75 for each post.
1	2	1.5	.75
2	4	3	.75
3	6	4.5	.75
4	8	6	.75
5	10	7.5	.75