Parabola Equation Check!

In the sketch below, click on the check box to show the equation.
Drag around point A (the vertex of the parabola).
Drag around point B.
Click on the check box to hide the equation again.

Drag around points A and B again.

What is the equation of this parabola?

Write down the equation on a piece of paper. Click on the check box to check your answer!

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Steve Phelps, Created with GeoGebra