Using quadratic equation concepts, we have that the element of interest is the vertex.
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A quadratic equation has the following format:
[tex]y = ax^2 + bx + c[/tex]
When the ball is kicked, it is kicked from a height, then reaches it maximum height until it falls to the ground, so it is a concave down parabola, that is, [tex]a < 0[/tex].
The time it took for the ball reach the maximum height is the x-value of the vertex, given by:
[tex]x_v = -\frac{b}{2a}[/tex]
Thus, the element of interest is the vertex.
A similar problem is given at https://brainly.com/question/16858635
