<PRE><B>Question 490126</B>
Height , h metres of a model rocket above ground, t = seconds after launching is given by the equation h(t) = 4t(50-t). 
Sketch the graph show the co-ordinates of all intercepts and turning point.
h(t) = -4t^2+200t
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Vertical intercept: (0,0)
Horizontal intercept: (0,0)(50,0)
{{{graph(400,400,-10,60,-10,2600,-4x^2+200x)}}}
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I need to find the greatest height the rocket reaches, after how long does the rocket reach its greatest height and how long does the rockets flight last.
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Max occurs when t = -b/(2a) = -200/(2*-4) = 25 seconds
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Max height: h(25) = 4*25(25) = 2500 ft
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length of flight: 50 seconds
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Cheers,
Stan H.
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