[tex]\bf \qquad \qquad \textit{inverse proportional variation}
\\\\
\textit{\underline{y} varies inversely with \underline{x}}\qquad \qquad y=\cfrac{k}{x}\impliedby
\begin{array}{llll}
k=constant\ of\\
\qquad variation
\end{array}\\\\
-------------------------------[/tex]
[tex]\bf (\stackrel{x}{8},\stackrel{y}{1})\textit{ we know that }
\begin{cases}
x=8\\
y=1
\end{cases}\implies 1=\cfrac{k}{8}\implies 8=k
\\\\\\
therefore\qquad \boxed{y=\cfrac{8}{x}}
\\\\\\
(x,\stackrel{y}{3})\textit{ when y = 3, what is \underline{x}?}\qquad 3=\cfrac{8}{x}\implies x=\cfrac{8}{3}[/tex]