Notice the picture below
the directrix is above the focus point, meaning the parabola is vertical and is opening downwards
now, "p" is the distance from the vertex to the focus point or the directrix, so that means, the vertex is between those two fellows, over the axis of symmetry, x = -2, since "p" is 1 unit, that puts the vertex at -2,5
since the parabola is opening downwards, that means the "p" value is negative, so is -1
the directrix is above the focus point, meaning the parabola is vertical and is opening downwards
now, "p" is the distance from the vertex to the focus point or the directrix, so that means, the vertex is between those two fellows, over the axis of symmetry, x = -2, since "p" is 1 unit, that puts the vertex at -2,5
since the parabola is opening downwards, that means the "p" value is negative, so is -1