Question 922970: 9) Bart Simpson is sitting in a treehouse and fires a rock into the air with his (in)famous slingshot. While in flight, the rock’s distance above the ground is a quadratic function. At times 1,2, and 3 seconds after being fired, the rock is 68, 96, and 114 feet above the ground respectively.
a) Write the quadratic equation describing the rocks height as a function of time since it was fired.
b) What is the highest the rock will ever be above the ground?
c) How long after being fired with the rock hit the ground (assuming Bart missed Homer, who he was aiming at)
Answer by josmiceli(19441)   (Show Source):
You can put this solution on YOUR website! You are given points ( 1,68 ), ( 2,96 ), ( 3,114 )
The general fom is:
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(1) 
(2) 
(3) 
( I know the 1st term has to be negative, since that
is the term that accounts for the downward pull of gravity )
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Multiply both sides of (1) by  and
subtract (2) from (1)
(1) 
(2) 
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Now subtract (3) from (2)
(2)
(3) 
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From these, I get:
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plug these into (1), (2), or (3)
Find c, b, then a
I have to run
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