SOLUTION: The height h in feet of an object after t seconds is given by the function h=-16t^2+90t+4 how long will it take the object to hit the grown? Round to the nearest thousandth

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Question 80616: The height h in feet of an object after t seconds is given by the function
h=-16t^2+90t+4
how long will it take the object to hit the grown? Round to the nearest thousandth
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The height h in feet of an object after t seconds is given by the function
h=-16t^2+90t+4
how long will it take the object to hit the grown? Round to the nearest thousandth
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When it hits the ground its height will be zero.
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EQUATION:
-16t^2+90t+4=0
-8t^2+45t+2=0
t=[-45+-sqrt(45^2-4*-8*2)]/-16
t=[-45+-sqrt(2089]/-4
t= 5.669 seconds