Option C. the x-coordinate of the vertex.
The time is a x-coordinate, and the maximum height is the vertex of the parabola, then the time at which the ball will reach its maximum height is the x-coordinate of the vertex.
I don’t have any money to do so I don’t have to go to the bank tomorrow I have to get my truck to do
That would be the x-coordinate of the vertex.
You would be looking for the y-coordinate of the vertex (D).
In equations for physics problems like this, x always represents time. Since height is not a time, then we can ignore all x answers.
y will represent height in these problems, but we have to determine which we are looking for. The y-intercept would be when x = 0, or time = 0. This would be the initial height of the ball. Since we are assuming that it gets thrown up into the air, this is not what we are looking for. Therefore, we need the vertex's y-coordinate.