Answer:
So it will take the stone 1 (one) second to reach its maximum height.
Step-by-step explanation:
Notice that the mathematical quadratic expression given is that of a parabola with branches pointing down. This means that the maximum value for that parabola is at the vertex. Your expression is also given in vertex form:
[tex]f(x)=a\,(x-x_v)^2+y_v[/tex]
where the pair of coordinates [tex](x_v,y_v)[/tex] are the x coordinate of the vertex and the y coordinate of the vertex.
Since x in your case is the time the stone is on the air, then the maximum (vertex) is at the point (1, 45) where "1" is the time in seconds and 45 is the height of the stone in meters.
So it will take the stone 1 (one) second to reach its maximum height.
