SOLUTION: A rocket is launched from a cliff and it can be represented by the following function. h(t)= -16t squared + 80t + 384, where x is the time in seconds and h is the height of the roc

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons -> SOLUTION: A rocket is launched from a cliff and it can be represented by the following function. h(t)= -16t squared + 80t + 384, where x is the time in seconds and h is the height of the roc      Log On


   



Question 969451: A rocket is launched from a cliff and it can be represented by the following function. h(t)= -16t squared + 80t + 384, where x is the time in seconds and h is the height of the rocket. How long did it take the rocket to reach the maximum height?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
If we graph f(t)=-16t^2 + 80t + 384, we'd see a convex upward parabola. The ordinate scale is 75 feet per tick. The vertex has a t value (x-axis) equal to -b/2a, where b is the coefficient of the middle term, and a is the coefficient of the leading term.
Vertex t value is therefore (-80/-32)=+2.5 seconds=t
Height is (-16)(2.5^2) + 80(2.5) + 384

Height=-100 + 200 + 384= 484 feet.
graph%28300%2C200%2C-0.2%2C8%2C0%2C500%2C-%2816x%5E2%29%2B80x%2B384%29