Sam throws paper airplane. The height of the plane, in feet, can be modeled by the equation y=-162 -0.5)? + 9. What is the meaning of the vertex?
1) After 0.5 seconds, the airplane was 9 feet in the air.
2) After 16 seconds, the airplane was 9 feet in the air
3) After 9 seconds, the airplane was 0.5 feet in the air
4) After 8 seconds, the airplane was 0.5 feet in the air