Q. Determine the equation of the parabola with vertex (−8,5) and directrix y=−3.
Identify Parabola Type: Identify whether the parabola is vertical or horizontal based on the directrix.Directrix: y=−3 is a horizontal line.Type of parabola: Vertical
Vertex Form: Identify the vertex form of a vertical parabola.Vertex form of vertical parabola: y=a(x−h)2+k
Determine Direction: Determine if the parabola opens upward or downward.Vertex (−8,5) is above the directrix y=−3.The parabola opens upward.
Calculate Distance: Calculate the distance between the vertex and the directrix.y-value for the vertex: 5y-value for the directrix: −3Distance: ∣5−(−3)∣=5+3=8
Find Value of a: Determine the value of a.The distance between the vertex and directrix is 8, which is equal to 4a1.8=4a1Solve for a: a=4×81a=321
Write Parabola Equation: Write the equation of the parabola using the vertex form.Substitute 321 for a, −8 for h, and 5 for k.y=321(x−(−8))2+5y=321(x+8)2+5
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