PLEASE HELP QUICK
Suppose a particle is moving along the x-axis. The position, measured in feet, of the particle can be modeled by the quadratic equation y = 3x2 − 12x − 9, where x is time, in seconds. What does the number −9 represent for the quadratic function?
  The particle is 9 feet to the left of the origin.
The particle is moving left 9 feet per second.
The particle is accelerating at −9 feet per second squared.
The particle has stopped at 9 seconds.