Q. Write the equation in vertex form for the parabola with vertex (0,−2) and directrix y=6.Simplify any fractions.______
Identify Parabola Orientation: Since the directrix is y=6, the parabola is vertical and opens downward because the vertex (0,−2) is below the directrix.
Vertex Form of Parabola: The vertex form of a vertical parabola is y=a(x−h)2+k, where (h,k) is the vertex.
Calculate Distance to Directrix: The distance between the vertex and the directrix is ∣6−(−2)∣=8.
Determine Focus Value: Since the parabola opens downward, a is negative. The focus is the same distance from the vertex as the directrix, so a=−4⋅81=−321.
Substitute Values into Equation: Substitute a=−321 and the vertex (h,k)=(0,−2) into the vertex form equation: y=−321(x−0)2−2.
Simplify Equation: Simplify the equation: y=−321x2−2.
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