A parabola with focus (a, b ) and directrix y = c has the equation
[tex](x-a)^2+b^2-c^2=2(b-c)y[/tex]
In our case, (a, b) = (2, 7) and c = -1; therefore, the above becomes
[tex](x-2)^2+7^2-(-1)^2=2(7-(-1))y[/tex][tex](x-2)^2+48=16y[/tex][tex]\Rightarrow\textcolor{#FF7968}{(x-2)^2=16(y-3)}[/tex]
which is our answer!
