Question 1167951
It is 5 feet high, the constant in the equation.
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vertex is at x=-b/2a or -4/-1/7 or 28
when x=28 then y=-56+112+5=61 ft.
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it strikes the ground when y=0
rewrite quadratic as -x^2+56x+70=0 or x^2-56x-70=0
x=(1/2)(56+/- sqrt (3136+280)) sqrt term=58.45
x=57.22 ft.

{{{graph(300,300,-10,60,-5,70,(-1/14)x^2+4x+5)}}}