Given the height function below

Let us now plot the graph of the height function of the rocket.
Y-intercept
The point where a line or curve crosses the y-axis of a graph.
Therefore, the y-intercept of the function is 0.5m, which represents the constant value of rocket height.
Roots of the function
The roots of a function are the x-intercepts, which is the y-coordinate of points lying on the x-axis is zero.
Therefore, the roots of the function are

which represents the time at which the rocket is initially launched and the time at which the function hits the ground.
Vertex of the function
The point at which a parabola changes direction, corresponding to the minimum or maximum value of the quadratic function.
Therefore, the vertex of the function is

which represents the maximum time and height of the rocket.