The parabola has a negative a value, opens downward, and has a maximum at the vertex of (2,7). An example of this graph could be a soda bottle on a 4-foot table creating a downward parabolic spray.

The parabola has a negative a value, opens downward, and has a maximum at the vertex of (2,3). An example of this graph could be a soda bottle on the ground creating a downward parabolic spray.

The parabola has a negative a value, opens downward, and has a maximum at the vertex of (2,5). An example of this graph could be a soda bottle on a 2-foot table creating a downward parabolic spray.

The parabola has a positive a value, opens upward, and has a minimum at the vertex of (2,1). An example of this graph could be a soda bottle upside down on a table; therefore, the spray went downward instead of upward.