Question 604828
If a rocket is propelled upward from ground level at 98 m/sec, its height in meters after t seconds is given by h=-4.9t^2+98t. During what interval of time will the rocket be higher than 445.9m?
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Solve: 
-4.9t^2+98t-445.9 = 0
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Ans: 7< t < 13
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Cheers,
Stan H.