Q. Write the equation in vertex form for the parabola with vertex (0,0) and directrix y=3.Simplify any fractions.______
Identify Parabola Orientation: Since the directrix is y=3, which is a horizontal line, the parabola is vertical and opens either up or down.
Locate Vertex and Directrix: The vertex is at (0,0), and the directrix is above it at y=3, so the parabola opens downward.
Calculate Distance to Directrix: The distance between the vertex and the directrix is the absolute value of the difference in their y-coordinates, which is ∣0−3∣=3.
Use Formula to Find 'a': The value of 'a' in the vertex form equation y=a(x−h)2+k is related to the distance from the vertex to the directrix by the formula 4a=−distance, since the parabola opens downward.
Substitute Distance to Solve for 'a': Substitute the distance into the formula to find 'a': 4a=−3, so a=−43.
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