Q. Determine the equation of the parabola that opens up, has focus (0,4), and a focal diameter of 28 .
Identify standard form: Identify the standard form of a vertical parabola.The standard form of a vertical parabola is (x−h)2=4p(y−k), where (h,k) is the vertex and p is the distance from the vertex to the focus.
Determine vertex: Determine the vertex of the parabola.Since the parabola opens up and the focus is at (0,4), the vertex is directly below the focus. The focal diameter is 28, so the distance from the vertex to the focus (value of ′p′) is 228=14. Therefore, the vertex is at (0,4−14)=(0,−10).
Calculate value of 'p': Calculate the value of 'p'.The value of 'p' is half the focal diameter, so p=228=14.
Write parabola equation: Write the equation of the parabola using the vertex (h,k) and the value of p. Substitute h=0, k=−10, and p=14 into the standard form equation of a vertical parabola to get (x−0)2=4⋅14(y+10).
Simplify equation: Simplify the equation.The equation simplifies to x2=56(y+10).
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