Answer:
The ball is six feet above the ground after two seconds.
Step-by-step explanation:
The height of a projectile as a function of time is modeled by the function:

And we want to determine after how many seconds is the ball six feet above the ground.
In other words, we can let h(t) = 6 and solve for <em>t</em>. This yields:

Solve for <em>t: </em>
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By the Zero Product Property:

Hence:

In conclusion, the ball is six feet above the ground after two seconds.