The function [tex]h(t) = -49 t^2 + 98 t[/tex] models the height of a ball, [tex]h(t)[/tex], in feet, [tex]t[/tex] seconds after being launched upward. Which of the following is equivalent to this function and most easily reveals the length of time the ball is in the air?

A. [tex]h(t) = -49 t(t + 2)[/tex]
B. [tex]h(t) = 98 t - 49 t^2[/tex]
C. [tex]h(t) = -49 t(t - 2)[/tex]
D. [tex]h(t) = -49\left(t^2 - 2t\right)[/tex]



Answer :

Sure, let's break down the function [tex]\( h(t) = -49t^2 + 98t \)[/tex] step by step to find the equivalent form that most easily reveals the length of time the ball is in the air.

1. Original Function: [tex]\( h(t) = -49t^2 + 98t \)[/tex]

2. Factoring the Function:
We want to factor this quadratic expression to find an equivalent form.

Notice that both terms, [tex]\(-49t^2\)[/tex] and [tex]\(98t\)[/tex], have a common factor. We can factor out the greatest common factor, which in this case is [tex]\( -49t \)[/tex].

[tex]\( h(t) = -49t^2 + 98t \)[/tex]

Factor out [tex]\(-49t\)[/tex]:
[tex]\[ h(t) = -49t(t - 2) \][/tex]

3. Interpreting the Factored Form:
The factored form of the function is [tex]\( h(t) = -49t(t - 2) \)[/tex].

This form reveals the roots, or the solutions to the equation when [tex]\( h(t) = 0 \)[/tex]:
[tex]\[ -49t(t - 2) = 0 \][/tex]

The solutions to the equation are:
[tex]\[ t = 0 \quad \text{or} \quad t - 2 = 0 \implies t = 2 \][/tex]

These solutions represent the times when the ball is at height [tex]\( h(t) = 0 \)[/tex], which corresponds to the moments the ball is launched (at [tex]\( t = 0 \)[/tex]) and when it touches the ground again (at [tex]\( t = 2 \)[/tex]).

4. Conclusion:
The equivalent function that most easily reveals the length of time the ball is in the air is:
[tex]\[ h(t) = -49t(t - 2) \][/tex]

This form shows that the ball is in the air for [tex]\( 2 \)[/tex] seconds, from the time it is launched until it returns to the ground.

So, the answer is:
[tex]\[ h(t) = -49t(t - 2) \][/tex]