Why is the trajectory of an object a parabola? Who first discovered the parabola?

Why is the trajectory of an object a parabola? Who first discovered the parabola?

1) Parabola is a kind of conic curve. In the physical environment, the object is formed by free parabolic motion. When it reaches a certain height, it will fall and return to the ground under the influence of gravity. The distance from low to high and then to low is what we call parabola. All the points on the parabola are integrated. This is the masterpiece of the magical nature!
2) Apollonius, an ancient Greek mathematician, studied him deeply!