Inverse Variation Formula

Inverse variation: A constant product

Formula for Invervse Variation

Inverse variation occurs when two variables such as XY are always equation to some constant K.

Example of Inverse Variation

• XY = 100

The effect of this relationship is that when one variable decreases the other variable increases as summarized in the table below

X	Y	XY
1	100	100
2	50	100
4	25	100
5	20	100
10	10	100
20	5	100
25	4	100
50	2	100
100	1	100

Identify which equations below represent inverse variation.

Answer

If you compare each equation with the formula for inverse variation, the only two that are not inverse varation are 2 and 4.

x + y = 3 is the equation of a line

and 4 is acutally an example of direct variation (as opposed to inverse variation) because the larger x gets the larger y gets!