We have that
<span>y = -x</span>²<span>+8x
we know that
when the ball hint the ground is the x-intercepts of the graph
the x-intercepts is for y=0
so
0=-x</span>²+8x--------> x²-8x=0----> x*(x-8)=0
the solution is
x=0
x=8
the x intercepts are the points (0,0) and (8,0)
the distance between the x intercepts points =[8-0]-----> 8 ft
the answer is
8 ft
see the attached figure
<span>y = -x</span>²<span>+8x
we know that
when the ball hint the ground is the x-intercepts of the graph
the x-intercepts is for y=0
so
0=-x</span>²+8x--------> x²-8x=0----> x*(x-8)=0
the solution is
x=0
x=8
the x intercepts are the points (0,0) and (8,0)
the distance between the x intercepts points =[8-0]-----> 8 ft
the answer is
8 ft
see the attached figure