Quadratic Regression

Question

Been stuck on this problem and can't figure out how to get it going.

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

h(t) = 93.275, 107.1, 118.475, 127.4, 133.875, 137.9

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 2.6 seconds after it is thrown?

How long will it take the object to reach 34 meters?

Answer 1

This problem is similar to the one you posted earlier and is solved in the same way. You need to learn to do these on your own for your next test.

How high will the object be 2.6 seconds after it is thrown?

Just plug t = 2.6 into the h(t) equation and compute the answer.

h(2.6) = -4.9(2.6)² + 35(2.6) + 77 = ____

How long will it take the object to reach 34 meters?

34 meters is a height so set h(t) = 34 and solve for t:

34 = −4.9t² + 35t + 77

0 = −4.9t² + 35t + 43

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.