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## Homework Statement

A coin it thrown from the top of a building, and its height in metres above the ground after 0, 1, 2, 3, 4, and 5 seconds is recorded as follows: {200, 203, 202, 197, 188, 175}. algebraically determine the function that describes this situation and use it to determine when the coin lands on the ground.

## Homework Equations

Nil

## The Attempt at a Solution

The second level of differences is constant, so it has to be a quadratic problem.

With the help of my trusty TI calculator, I determined the function to be h(t) = -2t

^{2}+ 5t + 200

So, to determine when the penny hits the ground, I let h(t) = 0.

-2t

^{2}+ 5t + 200 = 0

From here I used the quadratic formula.

t = [ -(5) +/- [tex]\sqrt{}5^2 - 4(-2)(200)[/tex] ] / [ 2(-2) ]

t = 11.3278 and 8.8278

But, when I plug this back into the function I had, I do not get h(t) = 0

I am so very confused.

Please help. Thanks.