Inverse Variation

While direct variation describes a linear relationship between two variables, inverse variation describes another kind of relationship. We say y varies inversely with x (or as x, in some textbooks) if:

xy = k,

or, equivalently,

for some constant k.

This means that as x increases, y decreases and as x decreases, y increases.

The graph of the inverse variation equation is a hyperbola with center at (0, 0).

Inverse Variation Equation for 3 different values of k