Answer
$\quad (x-1)^{2}=-(y-2)$
Work Step by Step
Opens down. By Table 2,
$\begin{array}{|c|c|c|c|} \hline
{focus}&{directrix}&{equation}& ... opens\\ \hline
{(h,k-a)}&{y=k+a}&{(x-h)^{2}=-4a(y-k)}& down \\ \hline \end{array}$
Read from the graph: $\quad (h,k)=(1,2),$
so the equation has form $\quad (x-1)^{2}=-4a(y-2)$
Find $-4a$ by using the point on the graph (insert its coordinates into the equation)
$(2-1)^{2}=-4a(1-2)$
$1=4a$
$-4a=-1$
The equation is $\quad (x-1)^{2}=-(y-2)$
