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Fireworks for the annual Fourth of July show are launched straight up from a steel platform. The launch of the entire show is computer controlled. The height of a particular firework in meters above the ground is given by , where time, , is in seconds.

  1. What is the height of the platform?

    Substitute to find the height of the platform.

    Use the Quadratic Formula to find the roots. Average them to find the line of symmetry.

    You have now found the parameter in the general equation .
    The given equation has the same a value, .
    Solve for by substituting the point you found in part (a).

  2. What is the maximum height the firework reaches?

    The factored form reveals the intercepts. Remember to include the value in your factored equation.

  3. How many seconds until it hits the ground?