Quadratic Regression

Question

I have been stuck on this question for awhile now, any help is appreciated.

The table below shows the height, , in meters, of an object that is thrown off the top of a building as a function of , the time in seconds after it is thrown.

t = 0.5, 1, 1.5, 2, 2.5, 3

h(t) = 75.475, 88.5, 99.075, 107.2, 112.875, 116.1

The height of the object as a function of the number of seconds that have passed since the object was thrown can be expressed by: .

How high will the object be 2.8 seconds after it is thrown?

How long will it take the object to reach 25 meters?

Answer 1

Answer 2

How high will the object be 2.8 seconds after it is thrown?

Just plug t = 2.8 into the h(t) equation and compute the answer.

h(t=2.8) = -4.9(2.8)² + 33.4(2.8) + 60 = ____

How long will it take the object to reach 25 meters?

25 meters is a height so set h(t) = 25 and solve for t:

25 = −4.9t² + 33.4t + 60

0 = −4.9t² + 33.4t + 35

Solve using the quadratic formula and your calculator. You'll get two answers, one positive and one negative. Since we can't go back in time, the positive answer is the one you want.