Inverse Variations

If y decreases as x increases, and if the product of x and y is a constant, then the relationship forms an inverse variation. xy = k.

The product rule for inverse variations is:

x₁y₁ = x₂y₂

x₁y₁ = k

x₂y₂ = k

The graph of an inverse variation may look like this:

Note that y decreases as x increases in positive and negative direction.