Answer: 2 Dogs
Step-by-step explanation: The other dog never left the park
Range= 4
Range is the highest number minus the lowest number, 10-6=4
The axis of symmetry of a parabola in the form

is a vertical line

where k is the x coordinate of the vertex of the parabola.
The x coordinate of the vertex of the parabola is given by

which in your case is

So, the axis of symmetry is the line x=12.