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  1. Refer to page 362 of Principles of Mathematics 11.

    List four important characteristics of quadratic functions written in vertex form, .

    • (h, k) represents the vertex of the function.
    • The equation of the axis of symmetry is x = h.
    • When the function opens up, there is a minimum value of k.
    • When the function opens down, there is a maximum value of k.



  2. Using the equation of the function , explain how the following information could be determined. Use the graph to verify your responses.

    • the coordinates of the vertex

    The equation is in the form , where (h, k) is the vertex.

    The vertex is (1, -18).

    • the y-intercept

    Let x = 0

    • the equation of the axis of symmetry

    x = h
    x     = 1

    • the maximum or minimum y-value

    because a is positive, there is a minimum
    at y = -18