Any relation is x and y is said to be a Direct variation if one is a constant multiplier of the other .In other words we can say : when one variable changes the other changes in proportion to the first.
The Direct variation equation are of the type y=k.x
Here k is known as constant of proportionality .It has a fixed value.
The given equation is y=

If we compare this equation with y=k.x
Then k=
