# Is z = xy an inverse variation?

Jun 4, 2015

$z = x y$ is an inverse variation on $x$ and $y$; that is for a fixed value of $z$ multiplying one of $x$ or $y$ by any value $k$ will result in the other being divided by $k$

$z = x y$ is a direct variation on $x$ and $z$.

$z = x y$ is (also) a direct variation on $y$ and $z$.