[tex]\bf \qquad \qquad \textit{direct proportional variation}\\\\
\textit{\underline{y} varies directly with \underline{x}}\qquad \qquad y=kx\impliedby
\begin{array}{llll}
k=constant\ of\\
\qquad variation
\end{array}\\\\
-------------------------------[/tex]
[tex]\bf \textit{q varies directly with p}^2\qquad q=kp^2
\\\\\\
\textit{we also know that }
\begin{cases}
q=16\\
p=2
\end{cases}\implies 16=k2^2\implies \cfrac{16}{2^2}=k
\\\\\\
4=k\qquad therefore\qquad \boxed{q=4p^2}
\\\\\\
\textit{when p = 12, what is \underline{q}?}\qquad q=4(12^2)[/tex]
