Using the vertex of the quadratic equation, it is found that the stone reaches a maximum height of 221.0625 ft after 3.5625 s.
A quadratic equation is modeled by:
[tex]y = ax^2 + bx + c[/tex]
The vertex is given by:
[tex](x_v, y_v)[/tex]
In which:
[tex]x_v = -\frac{b}{2a}[/tex]
[tex]y_v = -\frac{b^2 - 4ac}{4a}[/tex]
Considering the coefficient a, we have that:
In this problem, considering initial velocity of v(0) = 114 and an initial height of h(0) = 18, the equation is:
h(t) = -16t² + 114t + 18.
Which is a quadratic equation with coefficients a = -16, b = 114, c = 18.
Hence:
[tex]x_v = -\frac{114}{2(-16)} = 3.5625[/tex]
[tex]y_v = -\frac{114^2 - 4(-16)(18)}{4(-16)} = 221.0625[/tex]
Hence, the stone reaches a maximum height of 221.0625 ft after 3.5625 s.
More can be learned about the vertex of a quadratic equation at https://brainly.com/question/24737967
