Question 1008914
When the equation has the form
{{{ f(t) = a*t^2 + b*t + c }}}, the
x-coordinate of the maximum is at
{{{ x[max] = -b/(2a) }}}
{{{ a = -16 }}}
{{{ b = 120 }}}
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(A)
{{{ x[max] = -120/(2*(-16)) }}}
{{{ x[max] = 15/4 }}}
{{{ x[max] = 3.75 }}} sec
(B)
{{{ s(t)= -16t^2 + 120t + 20 }}}
{{{ s(3.75) = -16*14.0625 + 120*3.75 + 20 }}}
{{{ s(3.75) = -225 + 450 + 20 }}}
{{{ s(3.75) = 245 }}}
The maximum height is 245 ft