[tex]~~~~~~\textit{vertical parabola vertex form} \\\\ y=a(x- h)^2+ k\qquad \begin{cases} \stackrel{vertex}{(h,k)}\\\\ \stackrel{"a"~is~negative}{op ens~\cap}\qquad \stackrel{"a"~is~positive}{op ens~\cup} \end{cases} \\\\[-0.35em] ~\dotfill\\\\ y = 6(x+1)^2-9\implies y = 6[x-(\stackrel{h}{-1})]^2\stackrel{k}{-9}\qquad \qquad \stackrel{vertex}{(-1~~,~~-9)}[/tex]
