Answer
$x^2=-44y$
Work Step by Step
Step 1. Based on the given conditions, we have $2p=-11-(11)=-22$ and $p=-11$ and the parabola opens downwards.
Step 2. The vertex is at $(0,\frac{11-11}{2})$ or $(0,0)$ and we can write the equation as $x^2=4(-11)y=-44y$
