An inverse variation is the one in which the product of x and y is a constant:
[tex]xy=k[/tex]
We can find the value of this constant by replace x and y for the given values:
[tex]\begin{gathered} (2)(4)=k \\ k=8 \end{gathered}[/tex]
Now, replace k in the initial equation and then solve for y:
[tex]\begin{gathered} xy=8 \\ y=\frac{8}{x} \end{gathered}[/tex]
It means that the relationship is:
[tex]y=\frac{8}{x}[/tex]
The graph of this relationship is:
