The vertex of the parabola is and the focus is at
.
The -coordinates of the vertex and focus are same, hence the equation of the parabola is in the form of
.
Here is the vertex of the parabola and the focus of the parabola is
.
Here
and
.
.
Since , the parabola opens to the down.
The equation of parabola is .
Substitute and
.
.
Therefore, the equation of the parabola is .
The equation of the parabola is .