Answer:
The highest height the ball achieves is 4.5125 meters.
Step-by-step explanation:
Vertex of a quadratic function:
Suppose we have a quadratic function in the following format:
[tex]f(x) = ax^{2} + bx + c[/tex]
It's vertex is the point [tex](x_{v}, y_{v})[/tex]
In which
[tex]x_{v} = -\frac{b}{2a}[/tex]
[tex]y_{v} = -\frac{\Delta}{4a}[/tex]
Where
[tex]\Delta = b^2-4ac[/tex]
If a<0, the vertex is a maximum point, that is, the maximum value happens at [tex]x_{v}[/tex], and it's value is [tex]y_{v}[/tex].
In this question:
Quadratic function [tex]y = -0.2x^2 + 1.9x[/tex], which has [tex]a = -0.2, b = 1.9[/tex].
The maximum height of the ball is [tex]y_{v}[/tex].
Then
[tex]\Delta = b^2-4ac = (1.9)^2 - 4*(-0.2)(0) = 3.61[/tex]
[tex]y_{v} = -\frac{3.61}{4(-0.2)} = 4.5125[/tex]
The highest height the ball achieves is 4.5125 meters.