Throw a ball and its flight path is a parabola — the very same U-shaped curve as y = ax² + bx + c. The left view is the throw; the right view is that equation, graphed. They are one object.
Where the curve crosses the ground are its roots — the solutions. The ball lands on the right-hand root. The tip of the arc is the vertex, and its height is the peak of the flight.
The discriminant Δ = b² − 4ac counts the ground-crossings: two when Δ > 0, one graze when Δ = 0, and none when Δ < 0 — then the peak has sunk below the ground and the path never lands at all.
Drag the gold launch arrow to change speed and angle, or drag the peak on the graph. Every move reshapes both views, because both views are the one equation.
Something in the simulation stopped unexpectedly — the lesson continues without it. Nothing you did was wrong; you can move on.