Question

A quadratic function has a vertex at (3, -10) and passes through the point (0, 8). Which of the following equations best represents the function? O y = 2(x+3)² +8 O y = 2(x+3)² – 10 Oy=(x-3)²-10 O y = 2(x-3)² – 10​

Answer 1

`~~~~~~\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`

`\begin{cases} h=3\\ k=-10\\ \end{cases}\implies y=a(~~x-3~~)^2 + (-10)\hspace{4em}\textit{we also know that} \begin{cases} x=0\\ y=8 \end{cases} \\\\\\ 8=a(~~0-3~~)^2 + (-10)\implies 8=9a-10\implies 18=9a\implies \cfrac{18}{9}=a \\\\\\ 2=a\hspace{7em}y=2(~~x-3~~)^2 + (-10)\implies \boxed{y=2(x-3)^2-10}`